Novel grb2 associating polypeptides and nucleic acids encoding therefor

ABSTRACT

The present invention generally relates to novel GRB2 associating proteins and nucleic acids which encode these protein. In particular, these novel proteins possess inositol polyphosphate 5-phosphatase and phosphatidylinositol 5-phosphatase activities, important in growth factor mediated signal transduction. As such, the proteins, nucleic acids encoding the proteins, cells capable of expressing these nucleic acids and antibodies specific for these proteins will find a variety of uses in a variety of screening, therapeutic and other applications.

[0001] The present invention was made with government support under Grant Nos. HL32898 and HL16634, awarded by the National Institutes of Health. The government has certain rights in this invention.

[0002] The present invention generally relates to novel GRB2 associating polypeptides and nucleic acids which encode these polypeptides. In particular, these novel polypeptides possess inositol polyphosphate 5-phosphatase activity, important in growth factor mediated signal transduction. As such, the polypeptides, nucleic acids encoding the polypeptides, cells capable of expressing these nucleic acids and antibodies specific for the polypeptides will find a variety of uses in a wide range of screening, therapeutic and other applications.

BACKGROUND OF THE INVENTION

[0003] Receptor signaling pathways are the subject of widespread research efforts. A better understanding of these signaling pathways will lead to the design of new and more effective drugs in the treatment of many diseases. Of particular interest are the growth factor and related receptor signaling pathways and their role in cell growth and differentiation. Binding of a particular growth factor to its receptor on the cell plasma membrane can stimulate a wide variety of biochemical responses, including changes in ion fluxes, activation of various kinases, alteration of cell shape, transcription of various genes and modulation of enzymatic activities in cellular metabolism.

[0004] Growth factors play a role in embryonic development, cancer, atherosclerosis and the responses of tissues to injury. Growth factors are involved in several normal developmental processes as well as in pathological conditions. Many growth factor receptors are tyrosine kinases whose signalling is dependent upon tyrosine phosphorylation of both the receptor and other molecules. Specific phosphorylated tyrosine residues on these receptors recruit soluble intracellular signaling molecules to the complex upon growth factor stimulation, thus initiating the growth factor signaling cascade. The signal can then proceed through a series of steps to the nucleus and other subcellular locations where the final effects of activation by the extracellular ligand are produced. Recruitment of molecules is often carried out by adapter molecules containing only protein-protein interaction domains with no associated enzymatic activity. By examining the molecules that interact with these adapters, important parts of the signaling mechanism can be discovered, monitored and controlled. One such adapter protein is GRB2, a 24 kDa cytosolic adapter protein containing two SH3 domains flanking an SH2 domain, which is known to be involved in linking many important molecules in signal transduction.

[0005] Because disregulation of the cellular processes involved in cell growth can have disastrous effects, it is important to understand and gain control over these processes. This requires identifying the participants in the signaling events that lead to mitogenesis and elucidating their mechanism of function. The identification of these participants is important for a wide range of diagnostic, therapeutic and screening applications. In particular, by knowing the structure of a particular participant in a growth factor activation cascade, one can design compounds which affect that cascade, to either activate an otherwise inactive pathway, or inactivate an overly active pathway. Similarly, having identified a particular participant in a growth factor cascade, one can also identify situations where that cascade is defective, resulting in a particular pathological state. The identification of participants in particular growth factor activation cascades is thus of critical importance for screening compounds that affect these cascades and treating a variety of disorders resulting from anomalies in these cascades, both as therapeutic agents and as model systems for identification of compounds which affect the pathway and thus may be useful as therapeutic agents. The present invention meets these and many other needs.

SUMMARY OF THE INVENTION

[0006] The present invention generally provides substantially pure polypeptides, comprising an amino acid sequence that is substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2), or biologically active fragments thereof.

[0007] The present invention also provides isolated nucleic acid segments, which encode a polypeptide having an amino acid sequence substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2), or biologically active fragments thereof.

[0008] Also provided are isolated antibodies that are specifically immunoreactive with a polypeptide having an amino acid sequence substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2) or its biologically active fragments.

[0009] In a further aspect, the present invention provides methods of using these polypeptides. In particular, the invention provides a method of determining whether a test compound is an agonist or antagonist of a GRB2/GA5Ptase interaction. The method comprises contacting GRB2 with GA5Ptase (SEQ ID NO:2) under conditions conducive to forming a GRB2/GA5Ptase complex, in the presence and absence of the test compound. The amount of GRB2/GA5Ptase complex formed in the presence and absence of the test compound is then determined. An increase or decrease in the amount of GRB2/GA5Ptase complex formed in the presence of the test compound is indicative that the test compound is an agonist or antagonist of GRB2/GA5Ptase interaction, respectively.

[0010] In a related aspect, the present invention provides a method for determining whether a test compound is an agonist or antagonist of an inositol polyphosphate 5-phosphatase activity. The method comprises incubating a mixture of inositol polyphosphate substrate and GA5Ptase, in the presence and absence of the test compound. The mixture is then assayed to determine the amount of GA5Ptase product formed in the presence and absence of the test compound. The amount of product of GA5Ptase activity in the presence of the test compound is compared to the amount of product of GA5Ptase activity in the absence of the test compound. An increase or decrease in the amount of product of GA5Ptase activity in the presence of the test compound is indicative that the test compound is an agonist or antagonist of an inositol polyphosphate 5-phosphatase activity, respectively.

[0011] The present invention also provides a method of identifying the presence of GRB2 in a sample. The method comprises incubating the sample with the polypeptide of the invention, and detecting binding between the polypeptide and a portion of the sample. This binding is indicative of the presence of GRB2 in the sample.

[0012] Also provided is a method of purifying GRB2 from a mixture of different proteins containing GRB2. The method comprises immobilizing the polypeptide of the invention, on a solid support. The mixture of proteins is then contacted with the solid support under conditions in which the polypeptide binds GRB2. The solid support is washed to remove unbound proteins, and GRB2 is eluted from the solid support.

[0013] The present invention also provides kits for practicing these methods.

[0014] In a further aspect, the present invention provides a method of treating a patient suffering from a proliferative disorder. The method comprises administering to the patient a therapeutically effective amount of the polypeptide of the invention.

[0015] The present invention also provides substantially pure polypeptides that are immunologically cross-reactive with antibodies to the GA5ptase polypeptides and fragments, described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 shows a schematic representation of the probe used to screen a λgt11 expression library.

[0017]FIG. 2 shows a ribbon diagram and dendrogram illustrating relative similarities between inositol polyphosphate 5-phosphatases. Numbers beside the nodes of the dendrogram indicate the percent identity and (similarity). The black bar above the ribbon representation of GA5Ptase indicates the region cloned by interaction with GRB2, whereas the “P” indicates the location of PXXP motifs.

[0018]FIG. 3 shows a schematic representation of GA5Ptase, GRB2 and GRB3.3 molecules used in Cos7 Immunoprecipitations.

[0019]FIG. 4 shows results of co-immunoprecipitation of GA5Ptase with wild type GRB2 (“GRB2 wt”), point mutations of GRB2 (“GRB2 P49L”, “GRB2 E89K”, “GRB2 S90N”, “GRB2 G203R”) and GRB3.3.

[0020]FIG. 5A shows c-Fos Serum Responsive Element (SRE) activation when co-expressed with various combinations of GRB2, c-Ras and GA5Ptase. The error bars indicate standard error of the mean of triplicate transfections.

[0021]FIG. 5B shows SRE activation when co-expressed as indicated with GA5Ptase, c-Ras and the various GRB2 point mutations used in the Cos7 co-immunoprecipitation experiments shown in FIG. 4.

[0022]FIG. 5C shows SRE activation when co-expressed as indicated with GA5Ptase, v-Ras and GrbRB2 point mutations.

[0023]FIG. 5D shows a comparison of SRE activation when co-expressed with GA5Ptase versus platelet inositol polyphosphate 5-phosphatase type-II (“5Ptase II”).

[0024]FIG. 6 shows the effect of varying concentration of Ins(1,3,4,5)P₄ on the rate of its hydrolysis by GA5Ptase.

[0025]FIGS. 7A and 7B show the immunoprecipitation of both GA5Ptase protein and Ins(1,3,4,5)P₄ hydrolyzing activity of GA5Ptase. HA-tagged GA5Ptase was immunoprecipitated with αHA antiserum. Following contact with protein A sepharose, the supernatant (•) and protein A sepharose pellet (°) were Western blotted against αHA antiserum (FIG. 7B) and assayed for ability to hydrolyze Ins(1, 3,4,5)P₄ (FIG. 7A).

[0026] FIGS. 8A-C show HPLC analysis of reaction products from incubation of GA5Ptase with Ins(1,3,4,5)P₄.

[0027]FIG. 8A shows conversion of ³H-Ins(1,3,4,5)P₄ to ³H-Ins(1,3,4)P₃ (peak) in the presence of GA5Ptase.

[0028]FIG. 8B shows the conversion of ³H-Ins(1,3,4,5)P₄ to ³H-Ins(3,4)P₂ (peak), in the presence of GA5Ptase and inositol polyphosphate 1-phosphatase.

[0029]FIG. 8C shows the conversion of ³H-Ins(1,3,4,5)P₄ to ³H-Ins(1,3)P₂ (peak) in the presence of GA5Ptase and inositol polyphosphate 4-phosphatase.

[0030]FIG. 9 shows the hydrolysis of PtdIns(3,4,5)P₃ by recombinant inositol polyphosphate 5-phosphatases. Specifically shown is a graph showing hydrolysis with GA5Ptase (open squares) and human inositol polyphosphate 5-phosphatase II (“5-Ptase II”) (closed squares). Also shown is a TLC autoradiogram indicating conversion of PtdIns(3,4,5)P₃ to PtdInsP₂ by GA5Ptase and 5-Ptase II (inset).

[0031]FIG. 10 shows the nucleotide sequence (SEQ ID NO:1) and deduced amino acid sequence (SEQ ID NO:2) of the GRB2 associating protein GA5Ptase.

[0032]FIG. 11 shows a comparison between the amino acid sequence of GA5Ptase (SEQ ID NO:2) and that of a number of other inositol polyphosphate 5-phosphatases. Level of shading indicates similarity in residue structure. Black boxes indicate a consensus sequence. The sequences shown are C. elegans inositol polyphosphate 5-phosphatase (“celegptase”) (SEQ ID NO:3), S. cereviseae inositol polyphosphate 5-phosphatase (“ysc5ptase”) (SEQ ID NO:4), GA5Ptase (SEQ ID NO:2), human 51c (“51c”) (SEQ ID NO:5), human inositol polyphosphate 5-phosphatase 75 kDa (“5ptaseii”) (SEQ ID NO:6), human ocr1 protein responsible for human oculocerebrorenal syndrome (“ocr1”) (SEQ ID NO:7), Arabidopsis inositol polyphosphate 5-phosphatase (“arab5ptase”) (SEQ ID NO:8) and canine inositol polyphosphate 5-phosphatase 43 kDa (“h5ptase43”)(SEQ ID NO:9). The identified consensus sequence is also provided (“consensus”) (SEQ ID NO:10).

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0033] I. General Description

[0034] The present invention generally provides novel GRB2 associating polypeptides. These polypeptides are generally involved in signal transduction pathways following growth factor activation. In particular, the polypeptides of the present invention contribute to the mediation of inositol polyphosphate based signal transduction pathways, following growth factor activation.

[0035] Also provided by the present invention are nucleic acids encoding these novel polypeptides, expression vectors containing these nucleic acids, cells capable of expressing these expression vectors, antibodies which specifically recognize and bind these polypeptides and methods of using these polypeptides and nucleic acids in screening and therapeutic applications.

[0036] The polypeptides of the present invention have been identified as possessing unique specificity for inositol polyphosphates. In particular, the polypeptides of the present invention have inositol polyphosphate 5-phosphatase activity, and more particularly, the ability to remove the 5-phosphate from D-myo-Inositol 1,3,4,5-tetrakisphosphate (“Ins(1,3,4,5)P₄”) and Phosphatidylinositol 3,4,5-trisphosphate (“PtdIns(3,4,5)P₃”), but not D-myo-Inositol 1,4,5-trisphosphate (“Ins(1,4,5)P₃”) or Phosphatidylinositol (4,5)-bisphosphate (“PtdIns(4,5)P₂”). Accordingly, the polypeptides of the present invention are generally referred to herein by the abbreviation GA5Ptase, for GRB2 Associating inositol polyphosphate 5-phosphatase.

[0037] Inositol polyphosphates have been broadly implicated in cell signalling pathways. For example, stimulation of cell surface receptors has been found to initiate hydrolysis of membrane-bound inositol lipid, which produces at least two second messengers: diacylglycerol (DAG) and inositol(1,4,5)trisphosphate. These messengers are generated by a membrane transduction process which comprises three main components: a receptor, a coupling G protein and phosphoinositidase C. DAG acts by stimulating protein kinase C, whereas Ins(1,4,5)P₃ releases calcium from internal stores (see, Berridge and Irvine, Nature (1989) 341:197-205).

[0038] PtdIns(3,4,5)P₃ in particular, is the product of phosphatidyl inositol 3-kinase (“PI3 kinase”), an important agonist activated signaling protein, stimulated in growth factor mediated signal transduction. PI3-kinase is known to be involved in the regulation of cell growth and oncogenic transformation (Cantley et al., Cell, 64:1657 (1993)). Upon growth factor receptor stimulation, the wild-type PI3-kinase is activated and can phosphorylate phosphatidylinositol (“PtdIns”) at the 3′ position of the inositol ring. These phosphatidylinositol 3-phosphates are candidate second messenger molecules. The PI3-kinase enzyme is found associated with receptor protein tyrosine kinases such as PDGF-R-β, CSF-1 receptor, Insulin receptor and IGF-1 receptor as well as non-receptor tyrosine kinase oncogenes, e.g., src, gag-abl and fyn. Studies on mutants of platelet-derived growth factor (PDGF) receptor have shown that PI3-kinase is a key mediator of PDGF-mediated mitogenic signaling (Fantl et al., Cell, 69:413 (1992); Valius et al., ibid., 73:321 (1993)). PDGF-R mutants that are unable to bind PI3-kinase are also unable to induce a mitogenic response after growth factor stimulation and unable to activate p21c-Ras (Ras). These data indicate that PI3-kinase acts upstream of Ras in PDGF-stimulated signaling. Studies also indicate that the PI3-kinase product, PtdIns(3,4,5)P₃ is not the final product produced during the initial phases of signaling, indicating further processing of this signaling molecule. Stephens, et al., Nature 351:33-39 (1991), Hawkins, et al., Nature 358:157-159 (1992).

[0039] The action of the polypeptides of the present invention upon the specific product of PI3-kinase implicates these polypeptides as important downstream mediators of growth factor activation signaling cascades. Furthermore, in addition to inositol polyphosphate 5-phosphatase activity, the polypeptides of the invention also associate with GRB2, in cell culture. GRB2 is an intracellular signalling molecule that is recruited to the cell membrane/receptor complex upon growth factor stimulation. GRB2 is specifically recruited to the PDGF, EGF and other tyrosine growth factor receptors. It is also in the signaling pathway that activates Ras upon growth factor stimulation. GRB2 is a small protein (24 kDa) that functions as an adapter molecule using its two SH3 domains and single SH2 domain to provide a bridge between other important signaling molecules. Clark, et al., Nature 356:340-344 (1992), Stern, et al., Mol. Biol. Cell 4:1175-1188 (1993). The ability of the polypeptides of the invention to specifically associate with GRB2 further indicates the importance of these polypeptides as downstream mediators of growth factor activation signal transduction, generally.

[0040] The polypeptides of the present invention have also been shown to activate signaling through the Fos serum response element (SRE) in fibroblast cells when these polypeptides are co-expressed with GRB2 and c-Ras. This activation is four to six fold over the activation seen with GRB2, Ras or GRB2/Ras alone. The Fos SRE is a gene that is known to be turned on early in growth factor activation, and has been identified as an upstream event for many response elements for cell growth. See, e.g., Janknecht et al., Carcinogenesis 16(3)443-450 (1995), Piechaczyk et al., Crit. Rev. Oncol./Hematol. 17(2):93-131 (1994), Maruta et al., Bioessays 16(7):489-496 (1994). The Fos gene is also responsive to a large number of growth factors. In particular, the Fos SRE is believed to be the direct target induced by growth factor stimulation through the Ras oncogene.

[0041] The combination of the activities and specificities of the polypeptides of the present invention implicates these polypeptides as key elements in the activation of Ras and as downstream molecules generally, in agonist activated signal transduction cascades.

[0042] II. Proteins and Polypeptides of the Invention

[0043] In one aspect, the present invention provides substantially pure, or isolated polypeptides that are generally characterized by one or more of the following activities: inositol polyphosphate 5-phosphatase activity; the ability to associate with GRB2; and/or the ability to enhance activation of the Fos SRE when co-expressed with c-Ras or c-Ras and GRB2. In particular, the polypeptides of the present invention will generally possess inositol polyphosphate 5-phosphatase activity, and be capable of removing the 5-phosphate from D-myo-Inositol 1,3,4,5-tetrakisphosphate (“Ins(1,3,4,5)P₄”) and Phosphatidylinositol 3,4,5-trisphosphate (“PtdIns(3,4,5)P₃”), but not D-myo-Inositol 1,4,5-trisphosphate (“Ins(1,4,5)P₃”) or Phosphatidylinositol (4,5)-bisphosphate (“PtdIns(4,5)P₂”).

[0044] The terms “substantially pure” or “isolated”, when referring to proteins and polypeptides, denotes those polypeptides that are separated from proteins or other contaminants with which they are naturally associated. A protein or polypeptide is considered substantially pure when that protein makes up greater than about 50% of the total protein content of the composition containing that protein, and typically, greater than about 60% of the total protein content. More typically, a substantially pure protein will make up from about 75 to about 90% of the total protein. Preferably, the protein will make up greater than about 90%, and more preferably, greater than about 95% of the total protein in the composition.

[0045] Particularly preferred polypeptides will have an amino acid sequence that is substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2), or biologically active fragments thereof. Still more preferred polypeptides include the GA5Ptase protein (SEQ ID NO:2) or biologically active fragments thereof.

[0046] In describing the polypeptides of the present invention, conventional amino acid abbreviations will generally be used as follows: Phenylalanine is Phe or F; Leucine is Leu or L; Isoleucine is Ile or I; Methionine is Met or M; Valine is Val or V; Serine is Ser or S; Proline is Pro or P; Threonine is Thr or T; Alanine is Ala or A; Tyrosine is Tyr or Y; Histidine is His or H; Glutamine is Gln or Q; Asparagine is Asn or N; Lysine is Lys or K; Aspartic Acid is Asp or D; Glutamic Acid is Glu or E; Cysteine is Cys or C; Tryptophan is Trp or W; Arginine is Arg or R; and Glycine is Gly or G. In the polypeptide notation used herein, the left-hand direction is the amino terminal direction and the right-hand direction is the carboxy-terminal direction, in accordance with standard usage and convention.

[0047] The term “biologically active fragment” as used herein, refers to portions of the proteins or polypeptides which portions possess a particular biological activity. For example, such biological activity may include the ability to bind a particular protein or substrate, block or otherwise inhibit an interaction between two proteins or between an enzyme and its substrate, or may include a particular catalytic activity. With regard to the polypeptides of the present invention, particularly preferred polypeptides or biologically active fragments include, e.g., polypeptides that possess one or more of the biological activities described above, such as the ability to associate or bind GRB2 or affect the binding of GRB2 to its ligand, e.g., GA5Ptase. Also included are those fragments that bind the GA5Ptase substrates described above, are capable of affecting the binding of GA5Ptase to those substrates or that are capable of affecting the hydrolysis of those substrates. Fragments possessing this catalytic activity are also termed “catalytically active fragments.” Fragments that are specifically recognized and bound by antibodies raised against the GA5Ptase polypeptides are also included in the definition of biologically active fragments. Such fragments are also referred to herein as “immunologically active fragments.” Particularly preferred polypeptides or biologically active fragments are capable of enhancing the activation of Fos SRE when co-expressed with Ras or Ras and GRB2.

[0048] Biologically active fragments of the polypeptides of the invention will generally be useful where it is desired to analyze a single particular biological activity of the polypeptide. For example, where the fragment is used in a model to screen for agonists or antagonists of GA5Ptase/GRB2 interaction (discussed in greater detail, below), it may be desirable to utilize only the GRB2 binding portion of the polypeptides of the invention. Similarly, therapeutic applications will generally target a single biological activity of the GA5Ptase signaling operation, e.g. GRB2 binding, substrate binding or substrate catalysis, and as such, peptides having fewer than all of these activities will be desired, as discussed in greater detail, below. Alternatively, such fragments may be useful where use of a full length protein is unsuitable for the particular application, e.g. therapeutic treatments where administration of full length proteins is difficult.

[0049] Generally, biologically active fragments of the above described proteins will be from about 5 to about 1000 amino acids in length. Typically, these peptides will be from about 10 to about 500 amino acids in length, more typically about 20 to about 250 amino acids in length, and preferably from about 50 to about 200 amino acids in length. Generally, the length of the fragment may depend, in part, upon the application for which the particular peptide is to be used. For example, for raising antibodies, the peptides may be of a shorter length, e.g., from about 5 to about 50 amino acids in length, whereas for binding applications, the peptides will generally have a greater length, e.g., from about 50 to about 1000 amino acids in length, preferably, from about 100 to about 500 amino acids in length, and more preferably, from about 100 to about 200 amino acids in length.

[0050] The terms “substantially homologous” when referring to polypeptides, refer comparatively to two amino acid sequences which, when optimally aligned, are at least about 75% homologous, preferably at least about 85% homologous more preferably at least about 90% homologous, and still more preferably at least about 95% homologous. Optimal alignment of sequences for aligning a comparison window may be conducted by the local homology algorithm of Smith and Waterman (1981) Adv. Appl. Math. 2:482, by the homology alignment algorithm of Needleman and Wunsch (1970) J. Mol. Biol. 48:443, by the search for similarity method of Pearson and Lipman (1988) Proc. Natl. Acad. Sci. (USA) 85:2444, or by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package Release 7.0, Genetics Computer Group, 575 Science Dr., Madison, Wis.).

[0051] The polypeptides of the present invention may also be characterized by their ability to bind antibodies raised against proteins having the amino acid sequence shown in FIG. 10 (SEQ ID NO:2). These antibodies recognize polypeptides that are homologous to the GA5Ptase polypeptide (SEQ ID NO:2). A variety of immunoassay formats may be used to select antibodies specifically immunoreactive with a particular protein or domain. For example, solid-phase ELISA immunoassays are routinely used to select monoclonal antibodies specifically immunoreactive with a protein. See Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Publications, New York, for a description of immunoassay formats and conditions that can be used to determine specific immunoreactivity. Antibodies to the polypeptides of the present invention are discussed in greater detail, below.

[0052] The polypeptides of the present invention may generally be prepared using recombinant or synthetic methods well known in the art. Recombinant techniques are generally described in Sambrook, et al., Molecular Cloning: A Laboratory Manual, (2nd ed.) Vols. 1-3, Cold Spring Harbor Laboratory, (1989). Techniques for the synthesis of polypeptides are generally described in Merrifield, J. Amer. Chem. Soc. 85:2149-2456 (1963), Atherton, et al., Solid Phase Peptide Synthesis: A Practical Approach, IRL Press (1989), and Merrifield, Science 232:341-347 (1986). In preferred aspects, the polypeptides of the present invention may be expressed by a suitable host cell that has been transfected with a nucleic acid of the invention, as described in greater detail below.

[0053] Biologically active fragments of the above described polypeptides may generally be identified and prepared using methods well known in the art. For example, selective proteolytic digestion, recombinant deletional methods or de novo peptide synthesis methods may be employed to identify portions of the above described peptides that possess the desired biological activity, e.g., GRB2 binding, substrate binding, catalytic activity and the like. See, e.g. Sambrook, et al.

[0054] Isolation and purification of the polypeptides of the present invention can be carried out by methods that are generally well known in the art. For example, the polypeptides may be purified using readily available chromatographic methods, e.g., ion exchange, hydrophobic interaction, HPLC or affinity chromatography, to achieve the desired purity. Affinity chromatography may be particularly attractive in allowing the investigator to take advantage of the specific biological activity of the desired peptide, e.g., ligand binding, presence of antigenic determinants or the like. For example, the polypeptides of the present invention may be purified by taking advantage of their ability to associate with GRB2. Such affinity purification methods are well known in the art. In particular, GRB2 may be coupled to a suitable solid support and contacted with a mixture of proteins containing the polypeptides of the invention under conditions conducive the association of these polypeptides with GRB2. Once bound to the immobilized GRB2, the solid support is washed to remove unbound material and/or nonspecifically bound proteins. The polypeptides of the invention may then be eluted from the solid support in substantially pure form by, e.g. a change in salt, pH or buffer concentration. Suitable solid supports for affinity purifications are well known in the art and are generally commercially available from, e.g. Pharmacia, Inc., or Sigma Chemical Co. Examples of such solid supports include agarose, cellulose, dextran, silica, polystyrene or similar solid supports.

[0055] In addition to those polypeptides and fragments described above, the present invention also provides fusion proteins which contain these polypeptides or fragments. The term “fusion protein” as used herein, generally refers to a composite protein, i.e., a single contiguous amino acid sequence, made up of two distinct, heterologous polypeptides which are not normally fused together in a single amino acid sequence. Thus, a fusion protein may include a single amino acid sequence that contains two similar or identical polypeptide sequences, provided that these sequences are not normally found together in a single amino acid sequence. Fusion proteins may generally be prepared using either recombinant nucleic acid methods, i.e. as a result of transcription and translation of a gene fusion, which fusion comprises a segment encoding a polypeptide of the invention and a segment encoding a heterologous protein, or by chemical synthesis methods well known in the art.

[0056] These fusion proteins may be prepared to exhibit a combination of properties or activities of the derivative proteins. Typical fusion proteins may include a polypeptide of the invention fused to a reporter polypeptide, e.g., a substrate, cofactor, inhibitor, affinity ligand, antibody binding epitope tag, or an enzyme which is capable of being assayed. Because of their ability to associate with the GRB2 protein, the polypeptides of the invention, when included as a portion of the fusion protein, may act as an affinity ligand to direct the activity of the fused protein directly to the GRB2 protein. In the case of a fusion protein including a reporter group, this allows the presence and or location of the GRB2 protein to be determined. More importantly, such fusions can also be readily used as a marker for determining the level of fusion protein/GRB2 interaction. Examples of some useful fusion partners which can also serve as reporter groups include affinity ligands and antibody binding epitopes, such as the influenza virus hemagglutinin (IHA) epitope tag, or glutathione-S-transferase. Other typical fusion partners include bacterial β-galactosidase, trpE, protein A, β-lactamase, α-amylase, alcohol dehydrogenase and yeast α-mating factor. See, e.g., Godowski et al., Science 241:812-816 (1988).

[0057] Also included within the present invention are amino acid variants of the above described polypeptides. These variants may include insertions, deletions and substitutions with other amino acids. For example, in some aspects, amino acids may be substituted with different amino acids having similar structural characteristics, e.g. net charge, hydrophobicity, or the like. For example, phenylalanine may be substituted with tyrosine, as a similarly hydrophobic residue. Glycosylation modifications, either changed, increased amounts or decreased amounts, as well as other sequence modifications are also envisioned.

[0058] Systematic substitution of one or more amino acids of a consensus sequence with a D-amino acid of the same type (e.g., D-lysine in place of L-lysine) may also be used to generate more stable peptides. In addition, constrained peptides comprising a consensus sequence or a substantially identical consensus sequence variation may be generated by methods known in the art (Rizo and Gierasch (1992) Ann. Rev. Biochem. 61: 387; for example, by adding internal cysteine residues capable of forming intramolecular disulfide bridges which cyclize the peptide. Similarly, modification of the amino or carboxy terminals may also be used to confer stabilizing properties upon the polypeptides of the invention, e.g., amidation of the carboxy-terminus or acylation of the amino-terminus. Substitution of amino acids involved in catalytic activity can be used to generate dominant negative inhibitors of signaling pathways.

[0059] Furthermore, although primarily described in terms of “proteins” or “polypeptides” one of skill in the art, upon reading the instant specification, will appreciate that these terms also include structural analogs and derivatives of the above-described polypeptides, e.g., polypeptides having conservative amino acid insertions, deletions or substitutions, peptidomimetics and the like. For example, in addition to-the above described polypeptides which consist only of naturally-occurring amino acids, peptidomimetics of the polypeptides of the present invention are also provided. Peptide analogs are commonly used in the pharmaceutical industry as non-peptide drugs with properties analogous to those of the template peptide. These types of non-peptide compounds are termed “peptide mimetics” or “peptidomimetics” (Fauchere, J. (1986) Adv. Drug Res. 15:29; Veber and Freidinger (1985) TINS p.392; and Evans et al. (1987) J. Med. Chem 30:1229, and are usually developed with the aid of computerized molecular modeling. Peptide mimetics that are structurally similar to therapeutically useful peptides may be used to produce an equivalent therapeutic effect. Generally, peptidomimetics are structurally similar to a paradigm polypeptide (i.e., a polypeptide that has a biological or pharmacological activity), such as naturally-occurring receptor-binding polypeptide, but have one or more peptide linkages optionally replaced by a linkage selected from the group consisting of: —CH₂NH—, —CH₂S—, —CH₂—CH₂—, —CH═CH— (cis and trans), —COCH₂—, —CH(OH)CH₂—, and —CH₂SO—, by methods known in the art and further described in the following references: Spatola, A. F. in Chemistry and Biochemistry of Amino Acids, Peptides, and Proteins, B. Weinstein, eds., Marcel Dekker, New York, p. 267 (1983); Spatola, A. F., Vega Data (March 1983), Vol. 1, Issue 3, “Peptide Backbone Modifications” (general review); Morley, J. S., Trends Pharm Sci (1980) pp. 463-468 (general review); Hudson, D. et al., Int J Pept Prot Res (1979) 14:177-185 (—CH₂NH—, CH₂CH₂—); Spatola, A. F. et al., Life Sci (1986) 38:1243-1249 (—CH₂—S); Hann, M. M., J Chem Soc Perkin Trans I (1982) 307-314 (—CH—CH—, cis and trans); Almquist, R. G. et al., J Med Chem (1980) 23:1392-1398 (—COCH₂—); Jennings-White, C. et al., Tetrahedron Lett (1982) 23:2533 (—COCH₂—); Szelke, M. et al., European Appln. EP 45665 (1982) CA: 97:39405 (1982) (—CH(OH)CH₂—); Holladay, M. W. et al., Tetrahedron Lett (1983) 24:4401-4404 (—C(OH)CH₂—); and Hruby, V. J., Life Sci (1982) 31:189-199 (—CH₂—S—).

[0060] Peptide mimetics may have significant advantages over polypeptide embodiments, including, for example: more economical production, greater chemical stability, enhanced pharmacological properties (half-life, absorption, potency, efficacy, etc.), altered specificity (e.g., a broad-spectrum of biological activities), reduced antigenicity, and others.

[0061] For many applications, it may be desirable to provide the polypeptides of the invention as labeled entities, i.e., covalently attached or linked to a detectable group, to facilitate identification, detection and quantification of the polypeptide in a given circumstance. These detectable groups may comprise a detectable protein group, e.g. an assayable enzyme or antibody epitope as described above in the discussion of fusion proteins. Alternatively, the detectable group may be selected from a variety of other detectable groups or labels, such as radiolabels (e.g., ¹²⁵I, ³²P or ³⁵S) or a chemiluminescent or fluorescent group. Similarly, the detectable group may be a substrate, cofactor, inhibitor or affinity ligand. Labeling of peptidomimetics usually involves covalent attachment of one or more labels, directly or through a spacer (e.g., an amide group), to non-interfering position(s) on the peptidomimetic that are predicted by quantitative structure-activity data and/or molecular modeling. Such non-interfering positions generally are positions that do not form direct contacts with the molecules to which the peptidomimetic binds (e.g., GRB2) to produce the therapeutic effect. Derivitization (e.g., labeling) of peptidomimetics should not substantially interfere with the desired biological or pharmacological activity of the peptidomimetic. Generally, peptidomimetics of peptides of the invention bind to their ligands (e.g., GRB2) with high affinity and/or possess detectable biological activity (i.e., are agonistic or antagonistic to one or more inositol polyphosphate 5-phosphatase mediated phenotypic changes).

[0062] III. Pharmaceutical Compositions

[0063] For a variety of applications, it may be desirable to provide the polypeptides or polypeptide fragments of the invention as part of a pharmaceutical composition, e.g., in combination with a pharmaceutically acceptable carrier. In such pharmaceutical compositions, the polypeptide of the present invention is also referred to as “the active ingredient.” Pharmaceutical formulations suitable for use in the present invention are generally described in Remington's Pharmaceutical Sciences, Mack Publishing Co., 17th ed. (1985).

[0064] The pharmaceutical compositions of the present invention are intended for parenteral, topical, oral, or local administration. Where the pharmaceutical compositions are administered parenterally, the invention provides pharmaceutical compositions that comprise a solution of the agents described above, e.g., proteins or polypeptides of the invention, dissolved or suspended in a pharmaceutically acceptable carrier, preferably an aqueous carrier. A variety of aqueous carriers may be used, e.g., water, buffered water, saline, glycine and the like. These compositions may be sterilized by conventional, well known methods, e.g., sterile filtration. The resulting aqueous solutions may be packaged for use as is, or lyophilized for combination with a sterile solution prior to administration. The compositions may also contain pharmaceutically acceptable auxiliary substances as required to approximate physiological conditions, such as pH adjusting and buffering agents, tonicity adjusting agents, wetting agents, and the like, for example sodium acetate, sodium lactate, sodium chloride, potassium chloride, calcium chloride, sorbitan monolaurate, triethanolamine oleate, etc.

[0065] For solid compositions, conventional nontoxic solid carriers may be used which include, for example, pharmaceutical grades of mannitol, lactose starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium carbonate, and the like. For oral administration, a pharmaceutically acceptable nontoxic composition may be formed by incorporating any of the normally employed excipients, such as the previously listed carriers, and generally, 10-95% of active ingredient, and more preferably 25-75% active ingredient. In addition, for oral administration of peptide based compounds, the pharmaceutical compositions may include the active ingredient as part of a matrix to prevent proteolytic degradation of the active ingredient by digestive process, e.g., by providing the pharmaceutical composition within a liposomal composition, according to methods well known in the art. See, e.g., Remington's Pharmaceutical Sciences, Mack Publishing Co., 17th Ed. (1985).

[0066] For aerosol administration, the polypeptides are generally supplied in finely divided form along with a surfactant or propellant. Preferably, the surfactant will be soluble in the propellant. Representative of such agents are the esters or partial esters of fatty acids containing from 6 to 22 carbon atoms, such as caproic, octanoic, lauric, palmitic, stearic, linoleic, linolenic, olesteric and oleic acids, with an aliphatic polyhydric alcohol or its cyclic anhydride. Mixed esters, such as mixed or natural glycerides may be employed. A carrier can also be included, as desired, as with, e.g., lecithin for intranasal delivery.

[0067] The amount of the above compositions to be administered to the patient will vary depending upon what is to be administered to the patient, the state of the patient, and the manner of administration. Typically, the polypeptides are administered in an amount sufficient to affect the growth factor activation cascade, and thereby cure or at least partially arrest the symptoms of the disease which is sought to be treated, and its associated complications. An amount adequate to accomplish this is termed “a therapeutically effective amount” as described below. Amounts effective for this use will depend many factors, including the severity of the disorder and the weight and general state of the patient, but will generally be in the range of from about 1 mg to about 5 g of active agent per day, preferably from About 50 mg per day to about 500 mg per day, and more preferably, from about 50 mg to about 100 mg per day, for a 70 kg patient.

[0068] IV. Nucleic Acids and Expression Vectors

[0069] In addition to the above described polypeptides, the present invention also provides isolated nucleic acids encoding these polypeptides, as well as expression vectors which include these polynucleotides. Generally, the isolated nucleic acids of the present invention encode a polypeptide which is capable of associating with GRB2, and/or possesses inositol polyphosphate 5-phosphatase activity. In preferred aspects, the nucleic acids of the invention encode a polypeptide having an amino acid sequence that is substantially homologous to the amino acid sequence shown in FIG. 10. More preferred are those isolated nucleic acid sequences that are substantially homologous to the nucleotide sequence shown in FIG. 10, or fragments thereof, and most preferred are those nucleic acid sequences having the nucleotide sequence shown in FIG. 10.

[0070] “Nucleic acids” of the present invention include RNA, cDNA, genomic DNA, synthetic forms and mixed polymers, both sense and antisense strands. Furthermore, different alleles of each isoform are also included. The present invention also provides recombinant nucleic acids which are not otherwise naturally occurring. The nucleic acids described herein also include self replicating plasmids and infectious polymers of DNA or RNA. Unless specified otherwise, conventional notation for nucleic acids is used herein. For example, as written, the left hand end of a single stranded polynucleotide sequence is the 5′-end, whereas the right-hand end is the 3′-end. The left hand direction of double-stranded polynucleotide sequences is referred to as the 5′ direction. The direction of 5′ to 3′ addition of nascent RNA transcripts is referred to as the transcription direction; sequence regions on the DNA strand having the same sequence as the RNA and which are 5′ to the 5′ end of the RNA transcript are referred to as “upstream sequences”; sequence regions on the DNA strand having the same sequence as the RNA and which are 3′ to the 3′ end of the RNA transcript are referred to as “downstream sequences”.

[0071] The nucleic acids of the present invention may be present in whole cells, cell lysates or in partially pure or substantially pure or isolated form. When referring to nucleic acids, the terms “substantially pure” or “isolated” generally refer to the nucleic acid separated from contaminants with which it is generally associated, e.g., lipids, proteins and other nucleic acids. The substantially pure or isolated nucleic acids of the present invention will be greater than about 50% pure. Typically, these nucleic acids will be more than about 60% pure, more typically, from about 75% to about 90% pure, and preferably, from about 95% to about 98% pure.

[0072] The DNA compositions will generally include a coding region which encodes a polypeptide possessing inositol polyphosphate 5-phosphatase activity and capable of associating with GRB2. Preferred nucleic acids will typically encode polypeptides having an amino acid sequence which is substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2), or biologically active fragments thereof. More preferred nucleic acids will comprise a segment having more than about 20 contiguous nucleotides from the nucleotide sequence shown in FIG. 10 (SEQ ID NO:1), with still more preferred nucleic acids having a nucleotide sequence that is substantially homologous to the nucleotide sequence shown in FIG. 10 (SEQ ID No:1). Most preferred nucleic acids are those which include the nucleotide sequence shown in FIG. 10 (SEQ ID NO:1).

[0073] The phrase “nucleic acid sequence encoding” refers to a nucleic acid which directs the expression of a specific protein or peptide. The nucleic acid sequences include both the DNA strand sequence that is transcribed into RNA and the RNA sequence that is translated into protein. The nucleic acid sequences include both the full length nucleic acid sequences as well as non-full length sequences derived from the full length protein. It being further understood that the sequence includes the degenerate codons of the native sequence or sequences which may be introduced to provide codon preference in a specific host cell.

[0074] Substantial homology in the nucleic acid context means that the segments, or their complementary strands, when compared, are the same when properly aligned, with the appropriate nucleotide insertions or deletions, in at least about 60% of the nucleotides, typically, at least about 70%, more typically, at least about 80%, usually, at least about 90%, and more usually, at least about 95% to 98% of the nucleotides. Alternatively, substantial homology exists when the segments will hybridize under selective hybridization conditions to a strand, or its complement, typically using a sequence of at least about 20 contiguous nucleotides derived from the nucleotide sequence shown in FIG. 10. However, larger segments will usually be preferred, e.g., at least about 30 contiguous nucleotides, more usually about 40 contiguous nucleotides, and preferably more than about 50 contiguous nucleotides. Selective hybridization exists when hybridization occurs which is more selective than total lack of specificity. See, Kanehisa, Nucleic Acid Res. 12:203-213 (1984).

[0075] There are various methods of isolating the nucleic acids which encode the polypeptides of the present invention. Typically, the DNA is isolated from a genomic or cDNA library using labeled oligonucleotide probes specific for sequences in the desired DNA. Restriction endonuclease digestion of genomic DNA or cDNA containing the appropriate genes can be used to isolate the DNA encoding the polypeptides of the invention. From the nucleotide sequence given in FIG. 10, a panel of restriction endonucleases can be constructed to give cleavage of the DNA in desired regions, i.e., to obtain segments which encode biologically active fragments of the polypeptides of the invention. Following restriction endonuclease digestion, DNA encoding the polypeptides of the invention is identified by its ability to hybridize with a nucleic acid probe in, for example a Southern blot format. These regions are then isolated using standard methods. See, e.g., Sambrook, et al., supra.

[0076] The polymerase chain reaction, or “PCR” can also be used to prepare nucleic acids which encode the polypeptides of the present invention. PCR technology is used to amplify nucleic acid sequences of the desired nucleic acid, e.g., the DNA which encodes the polypeptides of the invention, directly from mRNA, cDNA, or genomic or cDNA libraries. Alternatively, solid phase oligonucleotide synthesis methods may also be employed to produce the nucleic acids described herein. Such methods include the phosphoramidite method described by, e.g., Beaucage and Carruthers, Tetrahedron Lett. 22:1859-1862 (1981), or the triester method according to Matteucci, et al., J. Am. Chem. Soc., 103:3185 (1981), both incorporated herein by reference. A double stranded fragment may then be obtained, if desired, by annealing the chemically synthesized single strands together under appropriate conditions or by synthesizing the complementary strand using DNA polymerase with an appropriate primer sequence.

[0077] Appropriate primers and probes for amplifying the nucleic acids described herein, may be generated from analysis of the nucleic acid sequences described herein, e.g. at FIG. 10. Briefly, oligonucleotide primers complementary to the two 3′ borders of the DNA region to be amplified are synthesized. The PCR is then carried out using the two primers. See, e.g., PCR Protocols: A Guide to Methods and Applications (Innis, M., Gelfand, D., Sninsky, J. and White, T., eds.) Academic Press (1990). Primers can be selected to amplify various sized segments from the nucleic acid sequence.

[0078] The present invention also includes fragments of the above described nucleic acids. Such fragments will generally comprise a segment of from about 15 to about 150 nucleotides. These fragments can be useful as oligonucleotide probes in the methods of the present invention, or alternatively to encode the polypeptides or biologically active fragments of the present invention, described herein. Also provided are substantially similar nucleic acid sequences, allelic variations and natural or induced sequences of the above described nucleic acids. Also included are chemically modified and substituted nucleic acids, e.g. those which incorporate modified nucleotide bases or which incorporate a labelling group.

[0079] In one aspect, cDNA encoding the polypeptides of the present invention, or fragments thereof, may be readily employed as nucleic acid probes useful for obtaining genes which encode the polypeptides of the present invention. “Nucleic acid probes” may be DNA or RNA fragments. DNA fragments can be prepared, for example, by digesting plasmid DNA, or by use of PCR, or synthesized by either the phosphoramidite method described above. Where a specific sequence for a nucleic acid probe is given, it is understood that the complementary strand is also identified and included. The complementary strand will work equally well in situations where the target is a double-stranded nucleic acid.

[0080] Typical nucleic acid probes may be readily derived from the nucleotide sequence shown in FIG. 10 (SEQ ID NO:1), or alternatively, may be prepared from the amino acid sequence of the GA5Ptase protein, as shown in FIG. 10 (SEQ ID NO:2). In particular, probes may be prepared based upon segments of the amino acid sequence which possess relatively low levels of degeneracy, i.e., few or one possible nucleic acid sequences which encode therefor. Suitable synthetic DNA fragments may then be prepared. Such cDNA probes may be used in the design of oligonucleotide probes and primers for screening and cloning genes which encode the polypeptides of the invention or related polypeptides, e.g., using well known PCR techniques. These nucleic acids, or fragments may comprise part or all of the cDNA sequence that encodes the polypeptides of the present invention. Effective cDNA probes may comprise as few as 15 consecutive nucleotides in the cDNA sequence, but will often comprise longer segments. Further, these probes may further comprise an additional nucleotide sequence, such as a transcriptional primer sequence for cloning, or a detectable group for easy identification and location of complementary sequences.

[0081] cDNA or genomic libraries of various types may be screened for new alleles or related sequences using the above probes. The choice of cDNA libraries normally corresponds to tissue sources which are abundant in mRNA for the desired polypeptides. Phage libraries are normally preferred, but plasmid libraries may also be used. Clones of a library are spread onto plates, transferred to a substrate for screening, denatured, and probed for the presence of the desired sequences.

[0082] In addition to comprising a segment which encodes one or more of the above described polypeptides or biologically active fragments, the nucleic acids of the present invention may also comprise a segment encoding a heterologous protein, such that the gene is expressed to produce the two proteins as a fusion protein, as substantially described above.

[0083] Typically, the nucleic acids of the present invention will be used in expression vectors for the preparation of the polypeptides of the present invention, namely those polypeptides which possess inositol polyphosphate 5-phosphatase activity and that are capable of associating with GRB2. The phrase “expression vector” generally refers to nucleotide sequences that are capable of affecting expression of a structural gene in hosts compatible with such sequences. These expression vectors typically include at least suitable promoter sequences and optionally, transcription termination signals. Additional factors necessary or helpful in effecting expression may also be used as described herein. DNA encoding the polypeptides of the present invention will typically be incorporated into DNA constructs capable of introduction into and expression in an in vitro cell culture. Often, the nucleic acids of the present invention may be used to produce a suitable recombinant host cell. Specifically, DNA constructs will be suitable for replication in a prokaryotic host, such as bacteria, e.g., E. coli, or may be introduced into a cultured mammalian, plant, insect, yeast, fungi or other eukaryotic cell line. DNA constructs prepared for introduction into a particular host, e.g., bacteria or yeast, will typically include a replication system recognized by the host, the intended DNA segment encoding the desired polypeptide, and transcriptional and translational initiation and termination regulatory sequences operably linked to the polypeptide encoding segment. A DNA segment is operably linked when it is placed into a functional relationship with another DNA segment. For example, a promoter or enhancer is operably linked to a coding sequence if it stimulates the transcription of the sequence. DNA for a signal sequence is operably linked to DNA encoding a polypeptide if it is expressed as a preprotein that participates in the secretion of the polypeptide. Generally, DNA sequences that are operably linked are contiguous, and in the case of a signal sequence both contiguous and in reading phase. However, enhancers need not be contiguous with the coding sequences whose transcription they control. Linking is accomplished by ligation at convenient restriction sites or at adapters or linkers inserted in lieu thereof. The selection of an appropriate promoter sequence will generally depend upon the host cell selected for the expression of the DNA segment. Examples of suitable promoter sequences include prokaryotic, and eukaryotic promoters well known in the art. See, e.g., Sambrook et al., Molecular Cloning: A Laboratory Manual (2d ed.), vols. 1-3 Cold Spring Harbor Laboratory (1989). The transcriptional regulatory sequences will typically include a heterologous enhancer or promoter which is recognized by the host. The selection of an appropriate promoter will depend upon the host, but promoters such as the trp, lac and phage promoters, tRNA promoters and glycolytic enzyme promoters are known and available. See Sambrook et al., (1989).

[0084] Conveniently available expression vectors which include the replication system and transcriptional and translational regulatory sequences together with the insertion site for the polypeptide encoding segment may be employed. Examples of workable combinations of cell lines and expression vectors are described in Sambrook et al., and in Metzger et al., Nature 334:31-36 (1988). For example, where an insect host cell is selected as-the host cell of choice to express the polypeptide, the cDNA encoding the polypeptides of the invention may be cloned into a baculovirus expression vector (e.g. pV-IKS). The recombinant baculovirus may then be used to transfect a suitable insect host cell, e.g., Sf9 cells, which may then express the polypeptide. See, e.g., D. K. Morrison et al., Cell 58:649-657 (1989), M. D. Summers and G. E. Smith, A Manual of Methods for Baculovirus Vectors and Insect Cell Culture Procedures, Texas Agricultural Station, College Station, Tex. (1987).

[0085] V. Cell Lines

[0086] The vectors containing the DNA segments of interest, e.g., those encoding polypeptides of the invention as described above, can be transferred into the host cell by well known methods which may vary depending upon the type of host cell used. For example, calcium chloride transfection is commonly used for prokaryotic cells, whereas calcium phosphate treatment may be used for other hosts. See, Sambrook et al. The term “transformed cell” as used herein, includes the progeny of originally transformed cells, which progeny express the nucleic acids of the invention.

[0087] Techniques for manipulation of nucleic acids which encode the polypeptides of the present invention, i.e., subcloning the nucleic acids into expression vectors, labeling probes, DNA hybridization and the like, are generally described in Sambrook, et al., supra.

[0088] In recombinant methods, generally the nucleic acid encoding a peptide of the present invention is first cloned or isolated in a form suitable for ligation into an expression vector. After ligation, the vectors containing the nucleic acid fragments or inserts are introduced into a suitable host cell, for the expression of the polypeptide of the invention. The polypeptides may then be purified or isolated from the host cells. Methods for the synthetic preparation of oligonucleotides are generally described in Gait, Oligonucleotide Synthesis: A Practical Approach, IRL Press (1990).

[0089] VI. Antibodies

[0090] The nucleic acids and polypeptides of the present invention or fragments thereof, are also useful in producing antibodies, either polyclonal or monoclonal, which are specifically immunoreactive with the polypeptides of the present invention.

[0091] The phrase “specifically immunoreactive,” when referring to the interaction between an antibody of the invention and a particular protein, refers to an antibody that specifically recognizes and binds with relatively high affinity to the particular protein, such that this binding is determinative of the presence of the protein in a heterogeneous population of proteins and other biologics. Thus, under designated immunoassay conditions, the specified antibodies bind to a particular protein and do not bind in a significant amount to other proteins present in the sample. A variety of immunoassay formats may be used to select antibodies specifically immunoreactive with a particular protein. For example, solid-phase ELISA immunoassays are routinely used to select monoclonal antibodies specifically immunoreactive with a protein. See Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Publications, New York, for a description of immunoassay formats and conditions that can be used to determine specific immunoreactivity.

[0092] For production of polyclonal antibodies, an appropriate target immune system is selected, typically a mouse or rabbit, but also including goats, sheep, cows, guinea pigs, monkeys and rats. The substantially purified antigen or plasmid is presented to the immune system in a fashion determined by methods appropriate for the animal. These and other parameters are well known to immunologists. Typically, injections are given in the footpads, intramuscularly, intradermally or intraperitoneally. The immunoglobulins produced by the host can be precipitated, isolated and purified by routine methods, including affinity purification.

[0093] For monoclonal antibodies, appropriate animals will be selected and the desired immunization protocol followed. After the appropriate period of time, the spleens of these animals are excised and individual spleen cells are fused, typically, to immortalized myeloma cells under appropriate selection conditions. Thereafter, the cells are clonally separated and the supernatants of each clone are tested for the production of an appropriate antibody specific for the desired region of the antigen. Techniques for producing antibodies are well known in the art. See, e.g., Goding et al., Monoclonal Antibodies: Principles and Practice (2d ed.) Acad. Press, N.Y., and Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, New York (1988). Other suitable techniques involve the in vitro exposure of lymphocytes to the antigenic polypeptides or alternatively, to selection of libraries of antibodies in phage or similar vectors. Huse et al., Generation of Large Combinatorial Library of the Immunoglobulin Repertoire in Phage Lambda, Science 246:1275-1281 (1989). Monoclonal antibodies with affinities of 10⁸ liters/mole, preferably 10⁹ to 10¹⁰ or stronger, will be produced by these methods.

[0094] The antibodies generated can be used for a number of purposes, e.g., as probes in immunoassays, for inhibiting GRB2/GA5Ptase interaction, or interaction with other ligands, thereby inhibiting or reducing the growth factor signaling cascade, in diagnostics or therapeutics, or in research to further elucidate the mechanism of growth factor activation pathways, and particularly, the growth factor activation of Ras. Where the antibodies are used to block the interaction between two signaling molecules, e.g. GRB2 and GA5Ptase, the antibody will generally be referred to as a “blocking antibody.”

[0095] The antibodies of the present invention can be used with or without modification. Frequently, the antibodies will be labeled by joining, either covalently or non-covalently, a substance which provides for a detectable signal. Such labels include those that are well known in the art, such as the labels described previously for the polypeptides of the invention. Additionally, the antibodies of the invention may be chimeric, human-like or humanized, in order to reduce their potential antigenicity, without reducing their affinity for their target. Chimeric, human-like and humanized antibodies have generally been described in the art. Generally, such chimeric, human-like or humanized antibodies comprise hypervariable regions, e.g., complementarity determining regions (CDRs) from a mammalian animal, i.e., a mouse, and a human framework region. See, e.g., Queen, et al., Proc. Nat'l Acad. Sci. USA 86:10029 (1989), Verhoeyan, et al., Science 239:1534-1536 (1988). By incorporating as little foreign sequence as possible in the hybrid antibody, the antigenicity is reduced. Preparation of these hybrid antibodies may be carried out by methods well known in the art.

[0096] Preferred antibodies are those monoclonal or polyclonal antibodies which specifically recognize and bind the polypeptides of the invention. Accordingly, these preferred antibodies will specifically recognize and bind the polypeptides which have an amino acid sequence that is substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2). Still more preferred are antibodies which are capable of forming an antibody-ligand complex with the polypeptides of the invention, whereby the ability of the polypeptide to associate with GRB2, in vitro, is reduced, e.g. blocking antibodies.

[0097] VII. Methods of Use

[0098] The polypeptides, antibodies and nucleic acids of the present invention may be used in a variety of important applications. Such applications include but are not limited to screening applications for identifying compounds that affect the growth factor signal transduction pathways, also termed “signaling cascades,” and therapeutic applications for the treatment of proliferative cell disorders.

[0099] A. Screening Applications

[0100] In a particular aspect, the present invention provides methods of screening test compounds to determine whether the test compounds are capable of affecting growth factor activation signal transduction pathways. More particularly, the methods described herein are used to screen compounds for there ability to affect the interaction of the polypeptides of the invention, and their respective substrates and ligands, as these interactions are involved in growth factor activation signal transduction pathways, and particularly, the growth factor activation of Ras.

[0101] In one aspect, the present invention provides methods of screening whether a test compound is an agonist or antagonist of GRB2-mediated signal transduction. More specifically, the polypeptides of the present invention can be used as a model system of GRB2/GA5Ptase interaction, to screen for compounds which affect this interaction. An agonist, antagonist or test compound may be a chemical compound, a mixture of chemical compounds, a biological macromolecule, or an extract made from biological materials such as bacteria, plants, fungi, or animal cells or tissues. Typically, test compounds may include structural analogs or peptidomimetics which are derived from the polypeptides described herein, and particularly the biologically active fragments. Test compounds are evaluated for potential activity as agonists or antagonists of functions which result in signal transduction, by inclusion in screening assays described herein. An “agonist” will enhance the particular observed activity, e.g. GRB2 association or 5-phosphate cleavage, while an “antagonist” will diminish the particular observed activity. The terms “agonist” and “antagonist”, as used herein, do not imply a particular mechanism of function. Particularly targeted test compounds include polypeptide fragments of the polypeptides of the present invention and structural analogs or peptidomimetics of these peptides.

[0102] In a first aspect, the screening methods of the present invention typically involve the incubation of a polypeptide of the present invention, or a GRB2 associating fragment thereof, in the presence of GRB2 as well as a particular test compound. The mixture is then assayed to determine the levels of GRB2/polypeptide interaction by determining the amount of GRB2/polypeptide complex formed in the presence and absence of the test compound. Where the presence of the test compound results in an increase or decrease in the amount of complex formed, it will be indicative that the test compound is an agonist or antagonist of GRB2-mediated signal transduction, respectively.

[0103] For determination of the amount of GRB2/polypeptide complex formed, one may employ any number of a variety of well known assay methods. For example, immunoprecipitation of one polypeptide or protein that participates in the complex, followed by assaying the immunoprecipitate for the other participant, will generally indicate the amount of complex formed. For example, following co-incubation of the polypeptide of the invention with GRB2, in the presence of the test compound, the polypeptide may be immunoprecipitated using an antibody that recognizes and specifically binds an epitope in the polypeptide's sequence. This epitope may be a sequence that is endogenous to the polypeptide or may be exogenously introduced as a labeling group, e.g., an antibody binding epitope tag or assayable enzyme. Following immunoprecipitation, the precipitate may be assayed for the presence of the other participant in the complex, e.g., GRB2, which may also be labelled, albeit in a distinguishing manner, e.g., a radiolabel, separately assayable enzyme, distinct antibody binding epitope tag or the like.

[0104] In an alternative method, one of the participants in complex formation, e.g., a polypeptide of the invention, may be coupled with an appropriate reporter group, while another participant, e.g., GRB2, is immobilized upon a solid support. Useful reporter groups, or labels have been previously described herein, including, e.g. radiolabels, such as, ¹²⁵I, ³²P or ³⁵S, fluorescent or chemiluminescent groups, substrates, cofactors, inhibitors, affinity ligands, antibody binding epitope tags, or enzymes which are capable of being assayed, e.g. horseradish peroxidase, luciferase, or other readily assayable enzymes. These enzyme groups may be attached to the polypeptide of the present invention by chemical means or expressed as a fusion protein, as already described.

[0105] Screening is then carried out by contacting the labeled participant with the immobilized participant in the presence and absence of the test compound. The amount of reporter group that binds to the solid support-bound participant is indicative of the amount of complex formed. The level of polypeptide bound in the presence of the test compounds may then be compared to the levels bound in control experiments, e.g., in the absence of the test compounds.

[0106] A variety of solid supports may be used in these screening methods. For example, blot formats may be employed where the protein or polypeptide is spotted on an appropriate substrate, e.g., nitrocellulose, PVDF and the like. Alternatively, resin or bead formats may also be used as the solid supports, including beads of agarose, cellulose, silica, polystyrene, divinylbenzene and the like.

[0107] Where the test compound results in an increase in the level of polypeptide which associates with GRB2, it is indicative that the test compound is an agonist of GRB2/GA5Ptase interaction, and more particularly, the GRB2-mediated signal transduction pathway. Similarly, where the presence of the test compound results in a decrease in the level of polypeptide GRB2 complex formed, it is indicative that the test compound is an antagonist of that interaction and signal transduction pathway.

[0108] In another aspect, the polypeptides of the present invention can be used as a model system for screening test compounds to identify agonists or antagonists of inositol polyphosphate 5-phosphatase activity generally, and in particular the inositol polyphosphate 5-phosphatase activity of GA5Ptase. Because the processing of phosphatidylinositols and particularly, the cleavage of the 5-phosphate from PtdIns(3,4,5)P₃ has been linked to the activation of Ras, it will be desirable to provide a model system for screening compounds which block or otherwise inhibit this conversion, and thereby block Ras activation.

[0109] The methods for determining whether a test compound is an agonist or antagonist of the inositol polyphosphate 5-phosphatase activity of the polypeptides of the invention, are generally similar to the above described methods. In particular, these methods comprise incubating a polypeptide having the desired inositol polyphosphate 5-phosphatase activity, e.g., GA5Ptase or catalytically active fragments thereof, with its substrate in the presence and absence of the test compound. This incubation may be carried out in vitro or in vivo, e.g., using a transgenic animal model which has been engineered to express the polypeptides of the invention. For the polypeptides of the present invention, the appropriate substrate may generally be selected from, e.g. D-myo-Inositol 1,3,4,5-tetrakisphosphate (“Ins(1,3,4,5)P₄”) and Phosphatidylinositol 3,4,5-trisphosphate (“PtdIns(3,4,5)P₃”). Following a prescribed reaction time the reaction mixture is assayed for the production of the products of inositol polyphosphate 5-phosphatase activity on these substrates. Assaying for production of the various reaction products, e.g. Ins(1,3,4)P₃ from Ins(1,3,4,5)P₄, or PtdIns(3,4)P₂ from PtdIns(3,4,5)P₃, may be carried out by a variety of methods known in the art. For example, HPLC analysis can be readily used to quantitatively identify the above described reaction products, using, e.g. tritiated substrates, and the like (see Example 2, below). Similarly, on a more qualitative level, thin layer chromatography (TLC) can also be used to identify reaction products. The levels of the above described reaction products produced in the presence and absence of the test compound are then compared. Where the presence of the test compound results in an increase or decrease in the level of the reaction product produced by the polypeptide, it is indicative that the test compound is an agonist or antagonist of inositol polyphosphate 5-phosphatase activity, respectively, and more particularly, the inositol polyphosphate 5-phosphatase activity described herein.

[0110] In a related embodiment, the present invention also provides kits for carrying out the above described screening methods. The kits of the present invention generally include a polypeptide of the present invention, e.g. the GA5Ptase polypeptide or a biologically active fragment thereof, as well as a ligand of the polypeptide where the binding activity is to be screened, e.g., GRB2, or a substrate of that polypeptide where the inositol polyphosphate 5-phosphatase activity is to be screened, e.g., Ins(1,3,4,5)P₄, or PtdIns(3,4,5)P₃. One or more of these components may generally be provided in premeasured aliquots. The aliquots can be contained in any suitable container such as a vial or a tube. The polypeptide component can be provided in solution or in lyophilized form, and may be immobilized. The polypeptide preparation may also contain preservatives such as sodium azide or protease inhibitors such as EDTA. A carrier protein such as BSA or ovalbumin, usually between 0.5-5%, may also be included to stabilize the polypeptide. The solution form of GA5Ptase may contain up to 50% glycerol if the enzyme is to be stored frozen, e.g., at −20° C. to −70° C. If the GA5Ptase is provided in lyophilized form, the kit can include a reconstitution buffer to reconstitute the polypeptide, as well as a reaction buffer. Alternatively, the polypeptide can be added to the reaction buffer and the solution freeze dried. This form can be readily reconstituted in distilled water with the necessary salt components already present for the particular reaction to be screened, so that no additional reaction buffer need be supplied. Thus, depending on the form and composition of the polypeptide preparation, different buffers may be included in the kit and they may be provided in more than one aliquot. Although described in substantial detail herein, these buffers are generally optional. The appropriate substrate or ligand, depending upon the particular screening method used, may be provided in a similar fashion to that of the polypeptide component. The kits will also typically include additional reagents for carrying out the particular method, e.g. stains for detection, antibodies, solid supports, and the like, as well as detailed operating specifications for their use. For example, where binding interactions are being screened, the ligand component may generally be supplied within the kit, already coupled to an appropriate support.

[0111] Once identified, particular agonists or antagonists may then be used to enhance or block the activity of the polypeptides of the present invention. This may be particularly useful in therapeutic applications (see discussion, below).

[0112] B. Therapeutic Applications

[0113] In addition to the above described uses, the polypeptides and nucleic acids of the present invention may also be used in therapeutic applications for the treatment of human or non-human mammalian patients. The term “treatment” refers to the full spectrum of treatment for a given disorder from which the patient is suffering, including alleviation of some, most or all symptoms resulting from that disorder, to an outright cure for the particular disorder to prevention of the onset of the disorder.

[0114] As described previously herein, the polypeptides of the present invention have been implicated as providing a critical step in the growth factor activation cascade, and particularly the activation of Ras. Activation of Ras has been associated with a variety of proliferative disorders including atherosclerosis, inflammatory joint diseases, psoriasis, restenosis following angioplasty, and cancer.

[0115] Accordingly, treatment of the above described disorders can generally be carried out by blocking or inhibiting activation of Ras. This may generally be accomplished by blocking or inhibiting one or more of the activities of the GA5Ptase polypeptide which are involved in the signal transduction pathway which activates Ras, e.g., the polypeptide's ability to bind GRB2, or the polypeptide's ability to bind to or catalyze the dephosphorylation of its substrate.

[0116] Generally, inhibition of the particular activity may be carried out by providing a polypeptide of the invention which will compete with the endogenous GA5Ptase protein. For example, by administering to a patient an effective amount of a GRB2 associating fragment of the polypeptides, as described herein, one can out compete the endogenous GRB2 associating activity of the endogenous GA5Ptase protein, and thereby reduce the level of Ras activation. Similarly, by administering to the patient an effective amount of a substrate binding, although non-catalytic, fragment of the GA5Ptase peptide, as described herein, one can effectively out compete the naturally occurring GA5Ptase protein, and thus block cleavage of the substrate, and the ensuing activation cascade reactions.

[0117] The quantities of reagents necessary for effective therapy, also referred to herein as an “effective amount,” or “therapeutically effective amount,” will depend upon many different factors, including means of administration, target site, physiological state of the patient and other medicants administered. Thus, treatment doses will need to be titrated to optimize safety and efficacy. Typically, dosages used in vitro may provide useful guidance in the amounts useful for in situ administration of these reagents. Animal testing of effective doses for treatment of particular disorders will provide further predictive indication of human dosage. Generally, therapeutically effective amounts of the GA5Ptase containing polypeptides of the present invention will be from about 0.0001 to about 10 mg/kg, and more usually, from about 0.001 to about 0.1 mg/kg of the host's body weight. Various considerations are described, e.g., in Gilman et al., (Eds.), Goodman and Gilman's: The Pharmacological Basis of Therapeutics, (8th ed. 1990), Pergamon Press, and Remington's Pharmaceutical Sciences (7th ed. 1985) Mack Publishing Co., Easton, Penn. Methods of administration, also discussed in the above references, include, e.g., oral, intravenous, intraperitoneal or intramuscular administration, and local administration, including topical, transdermal diffusion and aerosol administration, for therapeutic, and/or prophylactic treatment. The active agent, i.e., the polypeptide component, will generally be administered in a composition additionally comprising a pharmaceutically acceptable carrier. Suitable pharmaceutically acceptable carriers include water, saline, buffers and other compounds described in, e.g., the Merck Index, Merck and Co., Rahway, N.J.

[0118] Constituents of pharmaceutical compositions, in addition to the active agents, include those generally known in the art for the various administration methods used. For example, oral forms generally include powders, tablets, pills, capsules, lozenges and liquids. Similarly, intravenous, intraperitoneal or intramuscular formulations will generally be dissolved or suspended in a pharmaceutically acceptable carrier, e.g., water, buffered water, saline and the like. Additionally, these compositions may include additional constituents which may be required to approximate physiological conditions, such as pH adjusting and buffering agents, tonicity adjusting agents, wetting agents and the like. For solid compositions, conventional nontoxic solid carriers may be used which include, e.g., pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium carbonate and the like.

[0119] Administration may also be carried out by way of a controlled release composition or device, whereby a slow release of the active ingredient allows continuous administration over a longer period of time.

[0120] Additionally, inositol polyphosphates play important roles in cell signaling pathways, the present invention can provide an exogenous regulatory mechanism in the treatment of disorders where these regulatory mechanisms are disfunctional. In particular, the treatment of a particular disorder may comprise gene therapy techniques involving the mutation, dysregulation or augmentation of levels of GA5ptase. For example, gene therapy techniques may involve the introduction into afflicted cells, of genes which encode a protein or polypeptide which possesses the activity of GA5ptase. This exogenously introduced protein may then augment existing levels of this activity in cells that may be otherwise deficient.

[0121] Strategies for gene therapy are reviewed in Friedmann, Science 244:1275 (9189). Genetic constructs encoding the PTB domain or functional derivative of that domain, can be used in these gene therapy techniques. Delivery of the genetic construct of interest, i.e., the nucleic acid encoding a GA5ptase protein or fragment, may be accomplished in vivo by administering the therapy vector to an individual patient, typically by systemic administration (e.g., intravenous, intraperitoneal, intramuscular, subdermal, or intracranial administration). Alternatively, the vector may be used to deliver nucleic acids to cells ex vivo, such as cells explanted from an individual patient or universal donor hematopoietic stem cells, neurons, etc, e.g., by transfection of the cells with nucleic acids of interest cloned into retroviruses. Following transfection, the cells are reimplanted into the patient, usually after selection for cells which have incorporated the nucleic acid. The infusion into the patient of transfected cells can replace cells which are dysfunctional for the particular regulatory scheme which results in the disorder being treated.

[0122] C. Affinity Probes

[0123] Because the polypeptides of the present invention associate with GRB2 proteins, and specifically, via the SH3 domains, these proteins or their biologically active fragments may be particularly useful as affinity probes or ligands. In particular, the proteins can be used to identify or capture GRB2 proteins from a mixture of different proteins.

[0124] Typically, use of the polypeptides of the present invention in identifying GRB2 proteins in a mixture of proteins may be carried out using a Western blotting format. In particular, the mixture of proteins may be immobilized on a solid support, as described above. Immobilization may include simple spotting, electroblotting of SDS-PAGE gels and the like. The blot is then blocked using a nonspecific protein, i.e., BSA. Labeled polypeptides of the present invention may then be used to interrogate the blot, binding to the immobilized GRB2.

[0125] The polypeptides of the present invention may also be used as affinity ligands to purify Grb2 proteins from a mixture of proteins. In particular, the polypeptide of the invention is coupled to a solid support. The support bound polypeptide is then contacted with the mixture of proteins containing the GRB2 protein under conditions that are conducive to GA5Ptase/GRB2 binding. The support is then washed to remove unbound and nonspecifically bound proteins. Substantially pure GRB2 may then be readily eluted from the support by, e.g. a change in salt, pH or buffer concentrations.

[0126] The present invention is further illustrated by the following examples. These examples are merely to illustrate aspects of the present invention and are not intended as limitations of this invention.

VIII. EXAMPLES Example-1 Cloning and Sequence Analysis of GA5Ptase

[0127] A bacterially expressed GST-GRB2 fusion protein containing a 5 amino acid RRASV heart muscle kinase site was purified and radioactively labeled with [³²P]ATP. The purified protein was used to screen a human placental λgt11 oligo dT primed cDNA library (Clonetech) using the guanidine-HCl denaturation/renaturation screening technique initially described by Blanar and Rutter, Science 256:1014-1018 (1992). A schematic of this protein is shown in FIG. 1. Because all GRB2, interacting clones obtained in the first round of screening encoded catalytic regions of protein tyrosine kinases, duplicate filters were probed with antiphosphotyrosine antibody to screen against SH2 domain interactions. One clone was identified that specifically interacted with GRB2 and was not tyrosine phosphorylated. Sequencing of this clone indicated that it was a partial cDNA clone with no similarity to any other protein or cDNA. Multiple PXXP motifs were present, indicating the likely contact region with the SH3 domains of GRB2. Northern blot analysis indicated a 4.3 kb long transcript with broad tissue distribution, the highest being in placenta. Purified GST-GA5Ptase fragment was produced by cloning the original λgt11 cDNA fragment (nucleotides 2687-4146) into pGex1. Smith, et al., Gene 67:31-40 (1988).

[0128] Binding specificity of this protein fragment for GRB2 was evaluated by Far-Western blots of the protein with roughly equal amounts of radioactively labeled GRB2, Vav SH3-SH2—SH3 domains (amino acids 648-844, Katzav, et al., Embo J. 8:2283-2290 (1989)), Nck SH3—SH3—SH3 domains (amino acids 1-249, Hu, et al., Mol. Cell. Biol. 15:1169-1174 (1995)) and p85 SH3 domain (amino acids 1-81, Klippel, et al., Mol. Cell. Biol. 12:1451-1459 (1992)). Only GRB2 bound specifically to the GST fused fragment of the newly cloned protein and no proteins bound GST itself. A full length cDNA clone was obtained by screening a λgt10 human placental cDNA library. This 4146 bp clone contained an open reading frame encoding a 976 amino acid protein. The predicted 110 kDa protein showed that it has significant homology to a family of proteins known as inositol polyphosphate 5-phosphatases. FIG. 2 shows a ribbon diagram and dendrogram indicating relative homology of GA5Ptase to a number of inositol polyphosphate 5-phosphatases. FIG. 11 also shows a direct sequence comparison of GA5Ptase to these other phosphatase sequences. Included in the comparison are the C. elegans inositol polyphosphate 5-phosphatase (“celegptase”) (SEQ ID NO:3), S. cereviseae inositol polyphosphate 5-phosphatase (“ysc5ptase”) (SEQ ID NO:4), GA5Ptase (SEQ ID NO:2), human 51c (“51c”) (SEQ ID NO:5), the 75 kDa human platelet inositol polyphosphate 5-phosphatase type-II (“5ptaseii”) (SEQ ID NO:6), the human ocr1 protein responsible for human oculocerebrorenal syndrome (“ocr1”) (SEQ ID NO:7), Arabidopsis inositol polyphosphate 5-phosphatase (“arab5ptase”) (SEQ ID NO:8) and canine inositol polyphosphate 5-phosphatase 43 kDa (“h5ptase43”) (SEQ ID NO:9). The identified consensus sequence is also provided (“consensus”) (SEQ ID NO:10).

Example-2 Characterization of Enzymatic activity of GA5Ptase

[0129] The next step was to characterize the nature of the activity of the GA5ptase protein. FIG. 6 illustrates the effect of varying concentration of Ins(1,3,4,5)P₄ on the rate of its hydrolysis by GA5Ptase. FIG. 7 illustrates the coprecipitation of GA5ptase and IP₄ hydrolyzing activity.

[0130] To ensure that GA5Ptase was in fact an inositol polyphosphate 5-phosphatase, ³H-Ins(1,3,4,5)P₄ (200 pmoles) was incubated with GA5Ptase (1 μg) for 1 hour at 37° C. An aliquot of the reaction mix was quenched with 500 μl cold water, mixed with 300 cpm ³²P-Ins(1,4,5)P₃ as an internal standard, and analyzed by Absorbosphere™ Sax HPLC using a NaPO₄ gradient. FIG. 8A shows the resulting chromatogram showing conversion of the Ins(1,3,4,5)P₄ to Ins(1,3,4)P₃ by GA5Ptase.

[0131] An aliquot of the reaction mix was then incubated with a purified recombinant inositol polyphosphate 1phosphatase (York, et al., Proc. Nat'l Acad. Sci. USA 87:9548-9552 (1990)), quenched with 500 μl cold water, mixed with 300 cpm ³²P-Ins(1,4)P₂ as an internal standard, and analyzed using Partisil™ 10 Sax HPLC using an NH₄COOH gradient. FIG. 8B shows that the product of GA5Ptase was converted by the inositol polyphosphate 1 phosphatase to Ins(3,4)P₂.

[0132] A further aliquot of the original reaction mix was incubated with a purified recombinant inositol polyphosphate 4-phosphatase, quenched with 500 μl cold water, mixed with ³²P-Ins(3,4)P₂ as an internal standard and again analyzed using Partisil 10 Sax HPLC using an NH₄COOH gradient. FIG. 8C shows that the product of GA5Ptase action on Ins(1,3,4,5)P₄ was converted by inositol polyphosphate 4-phosphatase to Ins(1,3)P₂. These assays confirm that GA5Ptase has inositol polyphosphate 5-phosphatase activity.

[0133] GA5Ptase (20 ng) and 5ptase II (31 ng) were separately incubated with 1400 cpm ³²P-PtdIns(3,4,5)P₃ in phosphatidylserine vesicles for 1, 3 or 10 minutes at 37° C. The reaction was stopped by addition of 30 μl chloroform/methanol (1:1). The chloroform layer was spotted on an oxalate-dipped silica gel TLC plate and developed using a solvent mixture of chloroform/acetone/methanol/acetic acid/water from the TLC plate and quantified by Cerenkov radiation. Production of PtdInsP₂ from PtdIns(3,4,5)P₃ is shown in FIG. 9, plotted as a function of time. Each point shown is the average of quadruplicate assays. The inset shows an autoradiogram of a TLC plate indicating conversion of PtdIns(3,4,5)P₃ to PtdInsP₂ by both GA5Ptase and 5ptase II.

Example-3 Co-Immunoprecipitation of GA5Ptase

[0134] Lysates from Balb 3T3 cells were immunoprecipitated with GRB2 antibody (Transduction Laboratories) and blotted with preimmune (P) and immune (I) GA5Ptase polyclonal antibodies. Co-immunoprecipitation of endogenous GA5Ptase with endogenous GRB2 was detected in unstimulated Balb 3T3 cells using antibodies raised against two different regions of GA5Ptase (amino acids 47-231 and 891-983). To define the interaction of GA5Ptase with GRB2, both molecules were co-expressed in Cos cells and co-immunoprecipitated (FIG. 4).

[0135] Cos7 cells were transiently transfected with GA5Ptase and either wild type or single point mutations of GRB2 or GRB3.3. Schematic illustrations of the sequence structure of each of these proteins is shown in FIG. 3. Point mutations were the human counterparts of natural C. elegans Sem-5 point mutations. After 2 days of growth, cell lysates were immunoprecipitated with either myc antibody 9E10 (FIG. 4, odd numbered lanes) or HA antibody 12CA5 (even numbered lanes) and blotted with the same HA and myc antibodies. Wild type GRB2 or molecules having 2 intact SH3 domains (E89K, S9ON, GRB3.3) did bind to full length GA5Ptase (closed circles) but not shorter GA5Ptase proteins. Mutations that disrupt binding of either SH3 domain (P49L, G203R) markedly reduced (shaded triangle) or eliminated (open triangle) full length GA5Ptase binding. This illustrates that GRB2 associates with GA5Ptase through both of its SH3 domains.

Example-4 Activation of Serum Response Element Upon co-Expression With Ras and GRB2

[0136] NIH 3T3 cells were transiently transfected with constructs encoding GRB2, GA5Ptase, c-Ras, GRB2/c-Ras, GA5Ptase/c-Ras, GA5Ptase/GRB2 and GA5Ptase/c-Ras/GRB2, as listed in FIGS. 5A-D, and the luciferase indicator plasmid p2FTL. This plasmid contains two copies of the c-fos serum response element (SRE) (−357 to −276) and the herpes simplex virus (HSV) thymidine kinase (TK) gene promoter (−200 to +70) driving the firefly luciferase gene. After growth for two days in serum depleted media, the cells were harvested and endogenous luciferase activity was measured in relative light units. Each value is the average of triplicate transfections, error bars represent standard error of the mean. Point mutations in GRB2 are the same as those indicated above.

[0137] Substantial synergistic activation of the Fos promoter occurred when all three cDNAs were expressed. GRB2 mutants that reduce or eliminate the binding to GA5Ptase did not activate the Fos SRE as well as wild type (FIGS. 5B and 5C), indicating the importance of the interaction between GA5Ptase and GRB2. Platelet inositol polyphosphate 5-phosphatase type II (“5Ptase II”), a 5ptase family member also possessing Ins(1,3,4,5)P₄ and PtdIns(3,4,5)P₃ hydrolyzing activity can substitute for GA5Ptase in its activation of cFos transcription (FIG. 5D). These results indicate the importance of GA5Ptase activity in Fos SRE activation.

[0138] While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be clear to one skilled in the art from a reading of this disclosure that various changes in form and detail can be made without departing from the true scope of the invention. All publications and patent documents cited in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication or patent document were so individually denoted.

1 10 4147 base pairs nucleic acid single linear DNA (genomic) CDS 17..2944 1 CGCCCACTAA TCCTTG ATG TTC ACC TTG TCC CCT GCC CCC AGA GAA GTC 49 Met Phe Thr Leu Ser Pro Ala Pro Arg Glu Val 1 5 10 ATC CGG ACC CTC CCA TCC CTG GAG TCT CTG CAG AGG TTA TTT GAC CAG 97 Ile Arg Thr Leu Pro Ser Leu Glu Ser Leu Gln Arg Leu Phe Asp Gln 15 20 25 CAG CTC TCC CCG GGC CTC CGT CCA CGT CCT CAG GTT CCT GGT GAG GCC 145 Gln Leu Ser Pro Gly Leu Arg Pro Arg Pro Gln Val Pro Gly Glu Ala 30 35 40 AAT CCC ATC AAC ATG GTG TCC AAG CTC AGC CAA CTG ACA AGC CTG TTG 193 Asn Pro Ile Asn Met Val Ser Lys Leu Ser Gln Leu Thr Ser Leu Leu 45 50 55 TCA TCC ATT GAA GAC AAG GTC AAG GCC TTG CTG CAC GAG GGT CCT GAG 241 Ser Ser Ile Glu Asp Lys Val Lys Ala Leu Leu His Glu Gly Pro Glu 60 65 70 75 TCT CCG CAC CGG CCC TCC CTT ATC CCT CCA GTC ACC TTT GAG GTG AAG 289 Ser Pro His Arg Pro Ser Leu Ile Pro Pro Val Thr Phe Glu Val Lys 80 85 90 GCA GAG TCT CTG GGG ATT CCT CAG AAA ATG CAG CTC AAA GTC GAC GTT 337 Ala Glu Ser Leu Gly Ile Pro Gln Lys Met Gln Leu Lys Val Asp Val 95 100 105 GAG TCT GGG AAA CTG ATC ATT AAG AAG TCC AAG GAT GGT TCT GAG GAC 385 Glu Ser Gly Lys Leu Ile Ile Lys Lys Ser Lys Asp Gly Ser Glu Asp 110 115 120 AAG TTC TAC AGC CAC AAG AAA ATC CTG CAG CTC ATT AAG TCA CAG AAA 433 Lys Phe Tyr Ser His Lys Lys Ile Leu Gln Leu Ile Lys Ser Gln Lys 125 130 135 TTT CTG AAT AAG TTG GTG ATC TTG GTG GAA ACA GAG AAG GAG AAG ATC 481 Phe Leu Asn Lys Leu Val Ile Leu Val Glu Thr Glu Lys Glu Lys Ile 140 145 150 155 CTG CGG AAG GAA TAT GTT TTT GCT GAC TCC AAA AAG AGA GAA GGC TTC 529 Leu Arg Lys Glu Tyr Val Phe Ala Asp Ser Lys Lys Arg Glu Gly Phe 160 165 170 TGC CAG CTC CTG CAG CAG ATG AAG AAC AAG CAC TCA GAG CAG CCG GAG 577 Cys Gln Leu Leu Gln Gln Met Lys Asn Lys His Ser Glu Gln Pro Glu 175 180 185 CCC GAC ATG ATC ACC ATC TTC ATC GGC ACC TGG AAC ATG GGT AAC GCC 625 Pro Asp Met Ile Thr Ile Phe Ile Gly Thr Trp Asn Met Gly Asn Ala 190 195 200 CCC CCT CCC AAG AAG ATC ACG TCC TGG TTT CTC TCC AAG GGG CAG GGA 673 Pro Pro Pro Lys Lys Ile Thr Ser Trp Phe Leu Ser Lys Gly Gln Gly 205 210 215 AAG ACG CGG GAC GAC TCT GCG GAC TAC ATC CCC CAT GAC ATT TAC GTG 721 Lys Thr Arg Asp Asp Ser Ala Asp Tyr Ile Pro His Asp Ile Tyr Val 220 225 230 235 ATC GGC ACC CAA GAG GAC CCC CTG AGT GAG AAG GAG TGG CTG GAG ATC 769 Ile Gly Thr Gln Glu Asp Pro Leu Ser Glu Lys Glu Trp Leu Glu Ile 240 245 250 CTC AAA CAC TCC CTG CAA GAA ATC ACC AGT GTG ACT TTT AAA ACA GTC 817 Leu Lys His Ser Leu Gln Glu Ile Thr Ser Val Thr Phe Lys Thr Val 255 260 265 GCC ATC CAC ACG CTC TGG AAC ATC CGC ATC GTG GTG CTG GCC AAG CCT 865 Ala Ile His Thr Leu Trp Asn Ile Arg Ile Val Val Leu Ala Lys Pro 270 275 280 GAG CAC GAG AAC CGG ATC AGC CAC ATC TGT ACT GAC AAC GTG AAG ACA 913 Glu His Glu Asn Arg Ile Ser His Ile Cys Thr Asp Asn Val Lys Thr 285 290 295 GGC ATT GCA AAC ACA CTG GGG AAC AAG GGA GCC GTG GGG GTG TCG TTC 961 Gly Ile Ala Asn Thr Leu Gly Asn Lys Gly Ala Val Gly Val Ser Phe 300 305 310 315 ATG TTC AAT GGA ACC TCC TTA GGG TTC GTC AAC AGC CAC TTG ACT TCA 1009 Met Phe Asn Gly Thr Ser Leu Gly Phe Val Asn Ser His Leu Thr Ser 320 325 330 GGA AGT GAA AAG AAA CTC AGG CGA AAC CAA AAC TAT ATG AAC ATT CTC 1057 Gly Ser Glu Lys Lys Leu Arg Arg Asn Gln Asn Tyr Met Asn Ile Leu 335 340 345 CGG TTC CTG GCC CTG GGC GAC AAG AAG CTG AGT CCC TTT AAC ATC ACT 1105 Arg Phe Leu Ala Leu Gly Asp Lys Lys Leu Ser Pro Phe Asn Ile Thr 350 355 360 CAC CGC TTC ACG CAC CTC TTC TGG TTT GGG GAT CTT AAC TAC CGT GTG 1153 His Arg Phe Thr His Leu Phe Trp Phe Gly Asp Leu Asn Tyr Arg Val 365 370 375 GAT CTG CCT ACC TGG GAG GCA GAA ACC ATC ATC CAG AAA ATC AAG CAG 1201 Asp Leu Pro Thr Trp Glu Ala Glu Thr Ile Ile Gln Lys Ile Lys Gln 380 385 390 395 CAG CAG TAC GCA GAC CTC CTG TCC CAC GAC CAG CTG CTC ACA GAG AGG 1249 Gln Gln Tyr Ala Asp Leu Leu Ser His Asp Gln Leu Leu Thr Glu Arg 400 405 410 AGG GAG CAG AAG GTC TTC CTA CAC TTC GAG GAG GAA GAA ATC ACG TTT 1297 Arg Glu Gln Lys Val Phe Leu His Phe Glu Glu Glu Glu Ile Thr Phe 415 420 425 GCC CCA ACC TAC CGT TTT GAG AGA CTG ACT CGG GAC AAA TAC GCC TAC 1345 Ala Pro Thr Tyr Arg Phe Glu Arg Leu Thr Arg Asp Lys Tyr Ala Tyr 430 435 440 ACC AAG CAG AAA GCG ACA GGG ATG AAG TAC AAC TTG CCT TCC TGG TGT 1393 Thr Lys Gln Lys Ala Thr Gly Met Lys Tyr Asn Leu Pro Ser Trp Cys 445 450 455 GAC CGA GTC CTC TGG AAG TCT TAT CCC CTG GTG CAC GTG GTG TGT CAG 1441 Asp Arg Val Leu Trp Lys Ser Tyr Pro Leu Val His Val Val Cys Gln 460 465 470 475 TCT TAT GGC AGT ACC AGC GAC ATC ATG ACG AGT GAC CAC AGC CCT GTC 1489 Ser Tyr Gly Ser Thr Ser Asp Ile Met Thr Ser Asp His Ser Pro Val 480 485 490 TTT GCC ACA TTT GAG GCA GGA GTC ACT TCC CAG TTT GTC TCC AAG AAC 1537 Phe Ala Thr Phe Glu Ala Gly Val Thr Ser Gln Phe Val Ser Lys Asn 495 500 505 GGT CCC GGG ACT GTT GAC AGC CAA GGA CAG ATT GAG TTT CTC AGG TGC 1585 Gly Pro Gly Thr Val Asp Ser Gln Gly Gln Ile Glu Phe Leu Arg Cys 510 515 520 TAT GCC ACA TTG AAG ACC AAG TCC CAG ACC AAA TTC TAC CTG GAG TTC 1633 Tyr Ala Thr Leu Lys Thr Lys Ser Gln Thr Lys Phe Tyr Leu Glu Phe 525 530 535 CAC TCG AGC TGC TTG GAG AGT TTT GTC AAG AGT CAG GAA GGA GAA AAT 1681 His Ser Ser Cys Leu Glu Ser Phe Val Lys Ser Gln Glu Gly Glu Asn 540 545 550 555 GAA GAA GGA AGT GAG GGG GAG CTG GTG GTG AAG TTT GGT GAG ACT CTT 1729 Glu Glu Gly Ser Glu Gly Glu Leu Val Val Lys Phe Gly Glu Thr Leu 560 565 570 CCA AAG CTG AAG CCC ATT ATC TCT GAC CCT GAG TAC CTG CTA GAC CAG 1777 Pro Lys Leu Lys Pro Ile Ile Ser Asp Pro Glu Tyr Leu Leu Asp Gln 575 580 585 CAC ATC CTC ATC AGC ATC AAG TCC TCT GAC AGC GAC GAA TCC TAT GGC 1825 His Ile Leu Ile Ser Ile Lys Ser Ser Asp Ser Asp Glu Ser Tyr Gly 590 595 600 GAG GGC TGC ATT GCC CTT CGG TTA GAG GCC ACA GAA ACG CAG CTG CCC 1873 Glu Gly Cys Ile Ala Leu Arg Leu Glu Ala Thr Glu Thr Gln Leu Pro 605 610 615 ATC TAC ACG CCT CTC ACC CAC CAT GGG GAG TTG ACA GGC CAC TTC CAG 1921 Ile Tyr Thr Pro Leu Thr His His Gly Glu Leu Thr Gly His Phe Gln 620 625 630 635 GGG GAG ATC AAG CTG CAG ACC TCT CAG GGC AAG ACG AGG GAG AAG CTC 1969 Gly Glu Ile Lys Leu Gln Thr Ser Gln Gly Lys Thr Arg Glu Lys Leu 640 645 650 TAT GAC TTT GTG AAG ACG GAG CGT GAT GAA TCC AGT GGG CCA AAG ACC 2017 Tyr Asp Phe Val Lys Thr Glu Arg Asp Glu Ser Ser Gly Pro Lys Thr 655 660 665 CTG AAG AGC CTC ACC AGC CAC GAC CCC ATG AAG CAG TGG GAA GTC ACT 2065 Leu Lys Ser Leu Thr Ser His Asp Pro Met Lys Gln Trp Glu Val Thr 670 675 680 AGC AGG GCC CCT CCG TGC AGT GGC TCC AGC ATC ACT GAA ATC ATC AAC 2113 Ser Arg Ala Pro Pro Cys Ser Gly Ser Ser Ile Thr Glu Ile Ile Asn 685 690 695 CCC AAC TAC ATG GGA GTG GGC CCC TTT GGG CCA CCA ATG CCC CTG CAC 2161 Pro Asn Tyr Met Gly Val Gly Pro Phe Gly Pro Pro Met Pro Leu His 700 705 710 715 GTG AAG CAG ACC TTG TCC CCT GAC CAG CAG CCC ACA GCC TGG AGC TAC 2209 Val Lys Gln Thr Leu Ser Pro Asp Gln Gln Pro Thr Ala Trp Ser Tyr 720 725 730 GAC CAG CCG CCC AAG GAC TCC CCG CTG GGG CCC TGC AGG GGA GAA AGT 2257 Asp Gln Pro Pro Lys Asp Ser Pro Leu Gly Pro Cys Arg Gly Glu Ser 735 740 745 CCT CCG ACA CCT CCC GGC CAG CCG CCC ATA TCA CCC AAG AAG TTT TTA 2305 Pro Pro Thr Pro Pro Gly Gln Pro Pro Ile Ser Pro Lys Lys Phe Leu 750 755 760 CCC TCA ACA GCA AAC CGG GGT CTC CCT CCC AGG ACA CAG GAG TCA AGG 2353 Pro Ser Thr Ala Asn Arg Gly Leu Pro Pro Arg Thr Gln Glu Ser Arg 765 770 775 CCC AGT GAC CTG GGG AAG AAC GCA GGG GAC ACG CTG CCT CAG GAG GAC 2401 Pro Ser Asp Leu Gly Lys Asn Ala Gly Asp Thr Leu Pro Gln Glu Asp 780 785 790 795 CTG CCG CTG ACG AAG CCC GAG ATG TTT GAG AAC CCC CTG TAT GGG TCC 2449 Leu Pro Leu Thr Lys Pro Glu Met Phe Glu Asn Pro Leu Tyr Gly Ser 800 805 810 CTG AGT TCC TTC CCT AAG CCT GCT CCC AGG AAG GAC CAG GAA TCC CCC 2497 Leu Ser Ser Phe Pro Lys Pro Ala Pro Arg Lys Asp Gln Glu Ser Pro 815 820 825 AAA ATG CCG CGG AAG GAA CCC CCG CCC TGC CCG GAA CCC GGC ATC TTG 2545 Lys Met Pro Arg Lys Glu Pro Pro Pro Cys Pro Glu Pro Gly Ile Leu 830 835 840 TCG CCC AGC ATC GTG CTC ACC AAA GCC CAG GAG GCT GAT CGC GGC GAG 2593 Ser Pro Ser Ile Val Leu Thr Lys Ala Gln Glu Ala Asp Arg Gly Glu 845 850 855 GGG CCC GGC AAG CAG GTG CCC GCG CCC CGG CTG CGC TCC TTC ACG TGC 2641 Gly Pro Gly Lys Gln Val Pro Ala Pro Arg Leu Arg Ser Phe Thr Cys 860 865 870 875 TCA TCC TCT GCC GAG GGC AGG GCG GCC GGC GGG GAC AAG AGC CAA GGG 2689 Ser Ser Ser Ala Glu Gly Arg Ala Ala Gly Gly Asp Lys Ser Gln Gly 880 885 890 AAG CCC AAG ACC CCG GTC AGC TCC CAG GCC CCG GTG CCG GCC AAG AGG 2737 Lys Pro Lys Thr Pro Val Ser Ser Gln Ala Pro Val Pro Ala Lys Arg 895 900 905 CCC ATC AAG CCT TCC AGA TCG GAA ATC AAC CAG CAG ACC CCG CCC ACC 2785 Pro Ile Lys Pro Ser Arg Ser Glu Ile Asn Gln Gln Thr Pro Pro Thr 910 915 920 CCG ACG CCG CGG CCG CCG CTG CCA GTC AAG AGC CCG GCG GTG CTG CAC 2833 Pro Thr Pro Arg Pro Pro Leu Pro Val Lys Ser Pro Ala Val Leu His 925 930 935 CTC CAG CAC TCC AAG GGC CGC GAC TAC CGC GAC AAC ACC GAG CTC CCG 2881 Leu Gln His Ser Lys Gly Arg Asp Tyr Arg Asp Asn Thr Glu Leu Pro 940 945 950 955 CAT CAC GGC AAG CAC CGG CCG GAG GAG GGG CCA CCA GGG CCT CTA GGC 2929 His His Gly Lys His Arg Pro Glu Glu Gly Pro Pro Gly Pro Leu Gly 960 965 970 AGG ACT GCC ATG CAG TGAAGC CCTCAGTGAG CTGCCACTGA GTCGGGA 2977 Arg Thr Ala Met Gln 975 GCCCAGAGGA ACGGCGTGAA GCCACTGGAC CCTCTCCCGG GACCTCCTGC TGGCTCCTCC 3037 TGCCCAGCTT CCTATGCAAG GCTTTGTGTT TTCAGGAAAG GGCCTAGCTT CTGTGTGGCC 3097 CACAGAGTTC ACTGCCTGTG AGACTTAGCA CCAAGTGCTG AGGCTGGAAG AAAAACGCAC 3157 ACCAGACGGG CAACAAACAG TCTGGGTCCC CAGCTCGCTC TTGGTACTTG GGACCCCAGT 3217 GCCTCGTTGA GGGCGCCATT CTGAAGAAAG GAACTGCAGC GCCGATTTGA GGGTGGAGAT 3277 ATAGATAATA ATAATATTAA TAATAATAAT GGCCACATGG ATCGAACACT CATGATGTGC 3337 CAAATGCTGT GCTAAGTGCT TTACGAACAT TCGTCATATC AGGATGACCT CGAGAGCTGA 3397 GGCTCTAGCA CCTAAAACCA CGTGCCCAAA CCCACCAGTT TAAAACGGTG TGTGTTCGGA 3457 GGGGTGAAAG CATTAAGAAG CCCAGTGCCC TCCTGGAGTG AGACAAGGGC TCGGCCTTAA 3517 GGAGCTGAAG AGTCTGGGTA GCTTGTTTAG GGTACAAGAA GCCTGTTCTG TCCAGCTTCA 3577 GTGACACAAG CTGCTTTAGC TAAAGTCCCG CGGGTTCCGG CATGGCTAGG CTGAGAGCAG 3637 GGATCTACCT GGCTTCTCAG TTCTTTGGTT GGAAGGAGCA GGAAATCAGC TCCTATTCTC 3697 CAGTGGAGAG ATCTGGCCTC AGCTTGGGCT AGAGATGCCA AGGCCTGTGC CAGGTTCCCT 3757 GTGCCCTCCT CGAGGTGGGC AGCCATCACC AGCCACAGTT AAGCCAAGCC CCCCAACATG 3817 TATTCCATCG TGCTGGTAGA AGAGTCTTTG CTGTTGCTCC CGAAAGCCGT GCTCTCCAGC 3877 CTGGCTGCCA GGGAGGGTGG GCCTCTTGGT TCCAGGCTCT TGAAATAGTG CAGCCTTTTC 3937 TTCCTATCTC TGTGGCTTTC AGCTCTGCTT CCTTGGTTAT TAGGAGAATA GATGGGTGAT 3997 GTCTTTCCTT ATGTTGCTTT TTCAACATAG CAGAATTAAT GTAGGGAGCT AAATCCAGTG 4057 GTGTGTGTGA ATGCAGAAGG GAATGCACCC CACATTCCCA TGATGGAAGT CTGCGTAACC 4117 AATAAATTGT GCCTTTCTCA CTCAAAACCC 4147 976 amino acids amino acid linear protein 2 Met Phe Thr Leu Ser Pro Ala Pro Arg Glu Val Ile Arg Thr Leu Pro 1 5 10 15 Ser Leu Glu Ser Leu Gln Arg Leu Phe Asp Gln Gln Leu Ser Pro Gly 20 25 30 Leu Arg Pro Arg Pro Gln Val Pro Gly Glu Ala Asn Pro Ile Asn Met 35 40 45 Val Ser Lys Leu Ser Gln Leu Thr Ser Leu Leu Ser Ser Ile Glu Asp 50 55 60 Lys Val Lys Ala Leu Leu His Glu Gly Pro Glu Ser Pro His Arg Pro 65 70 75 80 Ser Leu Ile Pro Pro Val Thr Phe Glu Val Lys Ala Glu Ser Leu Gly 85 90 95 Ile Pro Gln Lys Met Gln Leu Lys Val Asp Val Glu Ser Gly Lys Leu 100 105 110 Ile Ile Lys Lys Ser Lys Asp Gly Ser Glu Asp Lys Phe Tyr Ser His 115 120 125 Lys Lys Ile Leu Gln Leu Ile Lys Ser Gln Lys Phe Leu Asn Lys Leu 130 135 140 Val Ile Leu Val Glu Thr Glu Lys Glu Lys Ile Leu Arg Lys Glu Tyr 145 150 155 160 Val Phe Ala Asp Ser Lys Lys Arg Glu Gly Phe Cys Gln Leu Leu Gln 165 170 175 Gln Met Lys Asn Lys His Ser Glu Gln Pro Glu Pro Asp Met Ile Thr 180 185 190 Ile Phe Ile Gly Thr Trp Asn Met Gly Asn Ala Pro Pro Pro Lys Lys 195 200 205 Ile Thr Ser Trp Phe Leu Ser Lys Gly Gln Gly Lys Thr Arg Asp Asp 210 215 220 Ser Ala Asp Tyr Ile Pro His Asp Ile Tyr Val Ile Gly Thr Gln Glu 225 230 235 240 Asp Pro Leu Ser Glu Lys Glu Trp Leu Glu Ile Leu Lys His Ser Leu 245 250 255 Gln Glu Ile Thr Ser Val Thr Phe Lys Thr Val Ala Ile His Thr Leu 260 265 270 Trp Asn Ile Arg Ile Val Val Leu Ala Lys Pro Glu His Glu Asn Arg 275 280 285 Ile Ser His Ile Cys Thr Asp Asn Val Lys Thr Gly Ile Ala Asn Thr 290 295 300 Leu Gly Asn Lys Gly Ala Val Gly Val Ser Phe Met Phe Asn Gly Thr 305 310 315 320 Ser Leu Gly Phe Val Asn Ser His Leu Thr Ser Gly Ser Glu Lys Lys 325 330 335 Leu Arg Arg Asn Gln Asn Tyr Met Asn Ile Leu Arg Phe Leu Ala Leu 340 345 350 Gly Asp Lys Lys Leu Ser Pro Phe Asn Ile Thr His Arg Phe Thr His 355 360 365 Leu Phe Trp Phe Gly Asp Leu Asn Tyr Arg Val Asp Leu Pro Thr Trp 370 375 380 Glu Ala Glu Thr Ile Ile Gln Lys Ile Lys Gln Gln Gln Tyr Ala Asp 385 390 395 400 Leu Leu Ser His Asp Gln Leu Leu Thr Glu Arg Arg Glu Gln Lys Val 405 410 415 Phe Leu His Phe Glu Glu Glu Glu Ile Thr Phe Ala Pro Thr Tyr Arg 420 425 430 Phe Glu Arg Leu Thr Arg Asp Lys Tyr Ala Tyr Thr Lys Gln Lys Ala 435 440 445 Thr Gly Met Lys Tyr Asn Leu Pro Ser Trp Cys Asp Arg Val Leu Trp 450 455 460 Lys Ser Tyr Pro Leu Val His Val Val Cys Gln Ser Tyr Gly Ser Thr 465 470 475 480 Ser Asp Ile Met Thr Ser Asp His Ser Pro Val Phe Ala Thr Phe Glu 485 490 495 Ala Gly Val Thr Ser Gln Phe Val Ser Lys Asn Gly Pro Gly Thr Val 500 505 510 Asp Ser Gln Gly Gln Ile Glu Phe Leu Arg Cys Tyr Ala Thr Leu Lys 515 520 525 Thr Lys Ser Gln Thr Lys Phe Tyr Leu Glu Phe His Ser Ser Cys Leu 530 535 540 Glu Ser Phe Val Lys Ser Gln Glu Gly Glu Asn Glu Glu Gly Ser Glu 545 550 555 560 Gly Glu Leu Val Val Lys Phe Gly Glu Thr Leu Pro Lys Leu Lys Pro 565 570 575 Ile Ile Ser Asp Pro Glu Tyr Leu Leu Asp Gln His Ile Leu Ile Ser 580 585 590 Ile Lys Ser Ser Asp Ser Asp Glu Ser Tyr Gly Glu Gly Cys Ile Ala 595 600 605 Leu Arg Leu Glu Ala Thr Glu Thr Gln Leu Pro Ile Tyr Thr Pro Leu 610 615 620 Thr His His Gly Glu Leu Thr Gly His Phe Gln Gly Glu Ile Lys Leu 625 630 635 640 Gln Thr Ser Gln Gly Lys Thr Arg Glu Lys Leu Tyr Asp Phe Val Lys 645 650 655 Thr Glu Arg Asp Glu Ser Ser Gly Pro Lys Thr Leu Lys Ser Leu Thr 660 665 670 Ser His Asp Pro Met Lys Gln Trp Glu Val Thr Ser Arg Ala Pro Pro 675 680 685 Cys Ser Gly Ser Ser Ile Thr Glu Ile Ile Asn Pro Asn Tyr Met Gly 690 695 700 Val Gly Pro Phe Gly Pro Pro Met Pro Leu His Val Lys Gln Thr Leu 705 710 715 720 Ser Pro Asp Gln Gln Pro Thr Ala Trp Ser Tyr Asp Gln Pro Pro Lys 725 730 735 Asp Ser Pro Leu Gly Pro Cys Arg Gly Glu Ser Pro Pro Thr Pro Pro 740 745 750 Gly Gln Pro Pro Ile Ser Pro Lys Lys Phe Leu Pro Ser Thr Ala Asn 755 760 765 Arg Gly Leu Pro Pro Arg Thr Gln Glu Ser Arg Pro Ser Asp Leu Gly 770 775 780 Lys Asn Ala Gly Asp Thr Leu Pro Gln Glu Asp Leu Pro Leu Thr Lys 785 790 795 800 Pro Glu Met Phe Glu Asn Pro Leu Tyr Gly Ser Leu Ser Ser Phe Pro 805 810 815 Lys Pro Ala Pro Arg Lys Asp Gln Glu Ser Pro Lys Met Pro Arg Lys 820 825 830 Glu Pro Pro Pro Cys Pro Glu Pro Gly Ile Leu Ser Pro Ser Ile Val 835 840 845 Leu Thr Lys Ala Gln Glu Ala Asp Arg Gly Glu Gly Pro Gly Lys Gln 850 855 860 Val Pro Ala Pro Arg Leu Arg Ser Phe Thr Cys Ser Ser Ser Ala Glu 865 870 875 880 Gly Arg Ala Ala Gly Gly Asp Lys Ser Gln Gly Lys Pro Lys Thr Pro 885 890 895 Val Ser Ser Gln Ala Pro Val Pro Ala Lys Arg Pro Ile Lys Pro Ser 900 905 910 Arg Ser Glu Ile Asn Gln Gln Thr Pro Pro Thr Pro Thr Pro Arg Pro 915 920 925 Pro Leu Pro Val Lys Ser Pro Ala Val Leu His Leu Gln His Ser Lys 930 935 940 Gly Arg Asp Tyr Arg Asp Asn Thr Glu Leu Pro His His Gly Lys His 945 950 955 960 Arg Pro Glu Glu Gly Pro Pro Gly Pro Leu Gly Arg Thr Ala Met Gln 965 970 975 398 amino acids amino acid linear protein Region 1..398 /note= “celegptase” 3 Met Asp Thr Lys Ile Thr Ile Phe Thr Tyr Asn Leu Ala Met Lys Ala 1 5 10 15 Ser Asp Ser Glu Ala Val His Lys Asn Leu Asn Gly Met Ile Asp Asp 20 25 30 His Thr His Leu Val Ala Ile Gly Leu Gln Glu Val Ala His Ser Glu 35 40 45 Thr Ile Gly Gly Ala Val Leu Thr Trp Ala Thr Thr Ile Ala Ser Trp 50 55 60 Met Asn Thr Asn Gly Arg Met Val Leu Leu Ala Lys Thr Phe Gln Ala 65 70 75 80 Thr Asn Gln Val Leu Ile Phe Gly Arg Lys Gln Leu Ile Gly Gln Ile 85 90 95 Lys Arg Ile Asp Tyr Arg Phe Gln Arg Asn Thr Met Gly Gly Leu Thr 100 105 110 Gly His Lys Gly Ser Ile Gly Val Arg Leu Gln Leu Ala Ser Pro Tyr 115 120 125 Ser Ile Val Pro Val Asp Ser His Phe Ile His Gly Pro Glu Asn Tyr 130 135 140 Gly Lys Arg Val Glu Gln Tyr His Thr Asn Arg Asn Cys Ser Phe Pro 145 150 155 160 Glu Asp Lys Ser Val Arg Ala Ala Phe Trp Phe Gly Asp Asp Asn Phe 165 170 175 Arg Val Glu Glu Asp Val Asn Thr Val Ile Arg Lys Ile Lys Asn Gly 180 185 190 Thr His Leu Glu Leu Leu Asp Thr Arg Glu Gln Leu Lys Arg Ala Leu 195 200 205 Val Glu Arg Asp Ala Phe Ile Gly Phe His Glu Gln Pro Val Thr Phe 210 215 220 Glu Pro Thr Tyr Arg Val Thr Val Gly Thr Thr Glu Gln Asp Gly Lys 225 230 235 240 Arg Val Pro Ser Trp Thr Asp Arg Ile Leu Tyr Lys Gly Asp Gly Ile 245 250 255 Thr Gly Leu Ser Tyr Thr Asn Asn Lys Lys Ala Val Ala Ser Asp His 260 265 270 Leu Pro Val Val Ala Met Phe Arg Met Thr Ala Pro Ala Ala Pro Lys 275 280 285 Pro Gln Trp Glu Val Ile Phe Glu His Leu Pro Thr Trp Tyr Thr Ser 290 295 300 Ile Pro Leu Val Gly Arg Phe Gln Val Asn Glu Leu Tyr Tyr Lys Glu 305 310 315 320 Asn Gly Ser Tyr Arg Asp Trp Ile Gly Val Phe Pro Ser Ser Ile Asn 325 330 335 Asp Cys Thr Thr Ala Thr Asn Trp Ile Tyr Ala Ala Thr Cys Phe Glu 340 345 350 Gln Val Ile Glu Gly Ser Lys Phe Leu Ala Cys Glu Phe Asn Asn Ile 355 360 365 Pro Ala Gly Asn Tyr Arg Leu Gly Tyr Phe Ser Cys His Leu His Cys 370 375 380 Leu Val Gly Leu Ser Lys Val Phe Gln Ile Val Glu Gln Pro 385 390 395 946 amino acids amino acid linear protein Region 1..946 /note= “ysc5ptase” 4 Met Arg Leu Phe Ile Gly Arg Arg Ser Arg Ser Ile Val Ile Ser Ser 1 5 10 15 Asn Asn Tyr Cys Leu Ser Phe Gln Arg Leu Arg Ser Ile Pro Gly Ala 20 25 30 Ser Ser Gln Gln Arg Gln Leu Ser Lys Thr Pro Ser Val Thr Ile Lys 35 40 45 Ser Tyr Pro Asp Thr Asp Leu Ser Ser Asp Ser Asn Tyr Leu Glu Val 50 55 60 Lys Ser Cys Ile Phe Asn Gly Leu Leu Gly Leu Val Cys Leu Asn Gly 65 70 75 80 Asp Ile Tyr Val Ala Val Ile Ser Gly Val Gln Asn Val Gly Phe Pro 85 90 95 Arg Trp Lys Leu Ile Asp His Gln Val Arg Pro Ser Glu Ser Ile Tyr 100 105 110 Lys Val Leu Asp Val Asp Phe Tyr Ser Leu Glu Asn Asp Val Phe Asp 115 120 125 Tyr Leu Leu Cys Glu Arg Ser Glu Gln Asn Tyr Asp Lys Leu Ile His 130 135 140 Glu His Pro Cys Gly Pro Leu Lys Lys Leu Phe Ser Asp Gly Thr Phe 145 150 155 160 Tyr Tyr Ser Arg Asp Phe Asp Ile Ser Asn Ile Val Lys Asn His Gly 165 170 175 Leu Ser His Asn Leu Glu Tyr Thr Val Asp Asn Gln Asp Leu Ser Phe 180 185 190 Ile Trp Asn Ala Asn Leu Ala Ser Glu Val Ile Asn Trp Arg Ser Lys 195 200 205 Ile Ser Asn Glu Glu Lys Gln Leu Phe Ala Asn Ala Gly Phe Leu Thr 210 215 220 Phe Val Ile Arg Gly Tyr Cys Lys Thr Ala Leu Ile Glu Asp Gly Pro 225 230 235 240 Asn Thr Ala Ser Ile Thr Ile Ile Ser Arg Ile Ser Thr Glu Ser Lys 245 250 255 Gln Asp Thr Leu Glu Leu Glu Gly Ile Ser Glu Asp Gly Arg Val Ser 260 265 270 Leu Phe Val Glu Thr Glu Ile Val Val Thr Thr Glu Lys Phe Ile Phe 275 280 285 Ser Tyr Thr Gln Val Asn Gly Ser Ile Pro Leu Phe Trp Glu Ser Val 290 295 300 Glu Ser Gln Leu Leu Tyr Gly Lys Lys Ile Lys Val Thr Lys Asp Ser 305 310 315 320 Ile Glu Ala Cys Gly Ala Glu Asp Arg His Phe Asp Asn Leu Thr Ser 325 330 335 Lys Tyr Gly Val Val Ser Ile Val Asn Ile Ile Lys Pro Lys Ser Glu 340 345 350 Ser Gln Glu Lys Leu Ala Leu Thr Tyr Lys Asp Cys Ala Glu Ser Lys 355 360 365 Gly Ile Lys Ile Thr Asn Ile Glu Tyr Ser Ser Ser Val Leu Thr Lys 370 375 380 Ser Pro His Lys Leu Leu Tyr Leu Leu Lys Gln Asp Ile Tyr Glu Phe 385 390 395 400 Gly Ala Phe Ala Tyr Asp Ile Ser Arg Gly Ile Tyr Phe Ala Lys Gln 405 410 415 Thr Gly Val Leu Arg Ile Ser Ala Phe Asp Ser Ile Glu Lys Pro Asn 420 425 430 Thr Val Glu Arg Leu Val Ser Lys Glu Val Leu Glu Leu Thr Asn Asn 435 440 445 Glu Ile Asp Val Phe Glu Leu Thr Ser Pro Phe Leu Asp Ala His Asp 450 455 460 Lys Leu Trp Ser Glu Asn Tyr Tyr Trp Leu Asp Arg Thr Tyr Thr Lys 465 470 475 480 His Thr Lys Asn Ser Gly Lys Tyr Thr Lys Val Tyr Ser Lys Leu Phe 485 490 495 Gly Ser Arg Val Arg Leu Tyr Asp Pro Leu His Ile Tyr Ile Ser Gln 500 505 510 Tyr Leu Lys Gln Leu Arg Ser Lys Tyr Thr Phe Glu Lys Asp Ile Ser 515 520 525 Ile Phe Ala Gly Thr Phe Asn Ile Ser Gly Lys Ile Pro Lys Asp Asp 530 535 540 Ile Lys Asp Trp Ile Phe Pro Lys Ser Met Ser Lys Glu Asp Phe Met 545 550 555 560 Ala Asp Leu Tyr Val Ile Gly Leu Glu Glu Val Val Glu Leu Thr Pro 565 570 575 Gly His Met Leu Ala Thr Asp Pro Tyr Val Arg Gln Phe Trp Glu Lys 580 585 590 Lys Ile Leu Thr Leu Leu Asn Gly Pro Gly Arg Lys Lys Lys Tyr Ile 595 600 605 Arg Leu Trp Ser Thr Gln Leu Gly Gly Ile Leu Leu Leu Leu Phe Met 610 615 620 Asn Glu Thr Glu Tyr Ser Lys Val Lys His Ile Glu Gly Asp Val Lys 625 630 635 640 Lys Thr Gly Phe Gly Gly Met Ala Ser Asn Lys Gly Ala Val Ala Val 645 650 655 Ser Phe Lys Tyr Ser Ala Thr Arg Phe Cys Val Leu Val Ser His Leu 660 665 670 Ala Ala Gly Leu Glu Asn Val Glu Gln Arg His Asn Asp Tyr Lys Thr 675 680 685 Ile Ala Lys Ser Ile Arg Phe Ser Lys Gly Leu Arg Ile Lys Asp His 690 695 700 Asp Ala Ile Phe Trp Phe Gly Asp Glu Asn Tyr Arg Ile Leu Met Ser 705 710 715 720 Asn Glu Asp Val Arg Arg Lys Ile Val Ser Lys Glu Tyr Ala Ser Leu 725 730 735 Phe Glu Lys Asp Gln Leu Asn Gln Gln Met Ile Ala Gly Glu Ser Phe 740 745 750 Pro Tyr Phe His Glu Met Ala Ile Asp Phe Pro Pro Thr Tyr Lys Phe 755 760 765 Asp Pro Gly Thr Lys Asn Tyr Asp Thr Ser Glu Lys Met Arg Leu Pro 770 775 780 Ala Trp Thr Asp Arg Ile Leu Ser Arg Gly Glu Val Leu Glu Gln Leu 785 790 795 800 Glu Tyr Lys Cys Cys Glu Asp Ile Leu Phe Ser Asp His Arg Pro Val 805 810 815 Tyr Ala Ile Phe Arg Ala Arg Val Thr Val Val Asp Glu Gln Lys Lys 820 825 830 Thr Thr Leu Gly Thr Gln Ile Tyr Glu Lys Ile Met Glu Arg Leu Glu 835 840 845 Gly Leu Asp Asp Asp Glu Lys Ile Ala Val Leu Ser Asp Asp Ala Phe 850 855 860 Val Ile Glu Ser Phe Glu Gly Ser Asp Ser Ile Ala Gly Pro Thr His 865 870 875 880 Ser Pro Thr Pro Ile Pro Glu Pro Lys Arg Gly Arg Lys Leu Pro Pro 885 890 895 Pro Ser Ser Asp Leu Lys Lys Trp Trp Ile Gly Ser Gly Lys Gln Val 900 905 910 Lys Val Val Leu Asp Val Asp Pro Ala Val Tyr Met Ile Asn Pro Lys 915 920 925 Arg Asp Pro Asn Pro Glu Val Glu Asn Glu Asp Glu Pro Leu Phe Ile 930 935 940 Glu Arg 945 1149 amino acids amino acid linear protein Region 1..1149 /note= “51c” 5 Met Cys Thr Arg Ile Ala Pro Cys Leu Met Glu Lys Ile Ser Trp Leu 1 5 10 15 Cys Arg Pro Arg Arg Val Cys Leu Cys Pro Ala Ser Arg Pro Trp Val 20 25 30 Ser Ser Ser Ala Cys Thr Pro Ser Pro Thr Arg Ala Leu Cys Ala Pro 35 40 45 Cys Leu Phe Leu Tyr Arg Val Ser Glu Ser Arg Thr His Arg Met Thr 50 55 60 Gly Met Pro Gln Met Gly Arg Met Arg Ser Pro Arg Cys Pro Arg Ala 65 70 75 80 Leu Ala Pro Pro Ala Phe Leu Pro Pro Thr Gly Pro Ser Ser Pro Leu 85 90 95 Pro Ala Pro Glu Thr Pro Thr Ala Pro Ala Ala Glu Ser Ala Pro Asn 100 105 110 Gly Leu Ser Thr Val Ser His Asp Tyr Leu Lys Gly Ser Tyr Gly Leu 115 120 125 Asp Leu Glu Ala Val Arg Gly Gly Ala Ser His Leu Pro His Leu Thr 130 135 140 Arg Thr Leu Ala Thr Ser Cys Arg Arg Leu His Ser Glu Val Asp Lys 145 150 155 160 Val Leu Ser Gly Leu Glu Ile Leu Ser Lys Val Phe Asp Gln Gln Ser 165 170 175 Ser Pro Met Val Thr Arg Leu Leu Gln Gln Gln Asn Leu Pro Gln Thr 180 185 190 Gly Glu Glu Glu Leu Glu Ser Leu Val Leu Lys Leu Ser Val Leu Lys 195 200 205 Asp Phe Leu Ser Gly Ile Gln Lys Lys Ala Leu Lys Ala Leu Gln Asp 210 215 220 Met Ser Ser Thr Ala Pro Pro Ala Pro Gln Pro Ser Thr Arg Lys Ala 225 230 235 240 Lys Thr Met Pro Val Gln Ala Phe Glu Val Lys Leu Asp Val Thr Leu 245 250 255 Gly Asp Leu Thr Lys Ile Gly Lys Ser Gln Lys Phe Thr Leu Ser Val 260 265 270 Asp Val Glu Gly Gly Arg Leu Val Leu Leu Arg Arg Gln Arg Asp Ser 275 280 285 Gln Glu Asp Trp Thr Thr Phe Thr His Asp Arg Ile Arg Gln Leu Ile 290 295 300 Lys Ser Gln Arg Val Gln Asn Lys Leu Gly Val Val Phe Glu Lys Glu 305 310 315 320 Lys Asp Arg Thr Gln Arg Lys Asp Phe Ile Phe Val Ser Ala Arg Lys 325 330 335 Arg Glu Ala Phe Cys Gln Leu Leu Gln Gln Met Lys Asn Lys His Ser 340 345 350 Lys Gln Asp Glu Pro Asp Met Ile Ser Met Phe Ile Gly Thr Trp Asn 355 360 365 Met Gly Ser Val Pro Pro Pro Lys Asn Val Thr Ser Trp Phe Thr Ser 370 375 380 Lys Gly Leu Gly Lys Thr Leu Asp Glu Val Thr Val Thr Ile Pro His 385 390 395 400 Asp Ile Tyr Val Phe Gly Thr Gln Glu Asn Ser Val Gly Asp Arg Glu 405 410 415 Trp Leu Asp Leu Leu Arg Gly Gly Leu Lys Glu Leu Thr Asp Leu Asp 420 425 430 Tyr Arg Pro Val Ala Met Gln Ser Leu Trp Asn Ile Lys Val Ala Val 435 440 445 Leu Val Lys Pro Glu His Glu Asn Arg Ile Ser His Val Ser Thr Ser 450 455 460 Ser Val Lys Thr Gly Ile Ala Asn Thr Leu Gly Asn Lys Gly Ala Val 465 470 475 480 Gly Val Ser Phe Met Phe Asn Gly Thr Ser Phe Gly Phe Val Asn Cys 485 490 495 His Leu Thr Ser Gly Ser Glu Lys Thr Ala Arg Arg Asn Gln Asn Tyr 500 505 510 Leu Asp Ile Leu Arg Leu Leu Ser Leu Gly Asp Arg Gln Leu Asn Ala 515 520 525 Phe Asp Ile Ser Leu Arg Phe Thr His Leu Phe Trp Phe Gly Asp Leu 530 535 540 Asn Tyr Arg Leu Asp Met Asp Ile Gln Glu Ile Leu Asn Tyr Ile Ser 545 550 555 560 Ser Lys Glu Phe Glu Pro Leu leu Arg Val Asp Gln Leu Asn Leu Glu 565 570 575 Arg Glu Lys His Lys Val Phe Leu Arg Phe Ser Glu Glu Glu Ile Ser 580 585 590 Phe Pro Pro Thr Tyr Arg Tyr Glu Arg Gly Ser Arg Asp Thr Tyr Ala 595 600 605 Trp His Lys Gln Lys Pro Thr Gly Val Arg Thr Asn Val Pro Ser Trp 610 615 620 Cys Asp Arg Ile Leu Trp Lys Ser Tyr Pro Glu Thr His Ile Val Cys 625 630 635 640 Asn Ser Tyr Gly Cys Thr Asp Asp Ile Val Thr Ser Asp His Ser Pro 645 650 655 Val Phe Gly Thr Phe Glu Val Gly Val Thr Ser Gln Phe Ile Ser Lys 660 665 670 Lys Gly Leu Ser Lys Thr Ser Asp Gln Ala Tyr Ile Glu Phe Glu Ser 675 680 685 Ile Glu Ala Ile Val Lys Thr Ala Ser Arg Thr Lys Phe Tyr Ile Glu 690 695 700 Phe Tyr Ser Thr Cys Leu Glu Glu Tyr Lys Lys Ser Phe Glu Asn Asp 705 710 715 720 Ala Gln Ser Ser Asp Asn Ile Asn Phe Leu Lys Val Lys Trp Ser Ser 725 730 735 Arg Gln Leu Pro Thr Leu Lys Pro Ile Leu Ala Asp Ile Glu Tyr Leu 740 745 750 Gln Asp Gln His Leu Leu Leu Thr Val Lys Ser Met Asp Gly Tyr Glu 755 760 765 Ser Tyr Gly Glu Cys Val Val Ala Leu Lys Ser Met Ile Gly Ser Thr 770 775 780 Ala Gln Gln Phe Leu Thr Phe Leu Ser His Arg Gly Glu Glu Thr Gly 785 790 795 800 Asn Ile Arg Gly Ser Met Lys Val Arg Val Pro Thr Glu Arg Leu Gly 805 810 815 Thr Arg Glu Arg Leu Tyr Glu Trp Ile Ser Ile Asp Lys Asp Glu Ala 820 825 830 Gly Ala Lys Ser Ser Pro Ile His Thr Leu Cys Tyr Met Arg Glu Pro 835 840 845 Arg Ser Gly Ser Arg Lys Pro Ala Phe Thr Glu Ala Ser Cys Pro Leu 850 855 860 Ser Arg Leu Phe Glu Glu Pro Glu Lys Pro Pro Pro Thr Gly Arg Pro 865 870 875 880 Pro Ala Pro Pro Arg Ala Ala Pro Arg Glu Glu Pro Leu Thr Pro Arg 885 890 895 Leu Lys Pro Glu Gly Ala Pro Glu Pro Glu Gly Val Ala Ala Pro Pro 900 905 910 Pro Lys Asn Ser Phe Asn Asn Pro Ala Tyr Tyr Val Leu Glu Gly Val 915 920 925 Pro His Gln Leu Leu Pro Pro Glu Pro Pro Ser Pro Ala Arg Ala Pro 930 935 940 Val Pro Ser Ala Thr Lys Asn Lys Val Ala Ile Thr Val Pro Ala Pro 945 950 955 960 Gln Leu Gly His His Arg His Pro Arg Val Gly Glu Gly Ser Ser Ser 965 970 975 Asp Glu Glu Ser Gly Gly Thr Leu Pro Pro Pro Asp Phe Pro Pro Pro 980 985 990 Pro Leu Pro Asp Ser Ala Ile Phe Leu Pro Pro Ser Leu Asp Pro Leu 995 1000 1005 Pro Gly Pro Val Val Arg Gly Arg Gly Gly Ala Glu Ala Arg Gly Pro 1010 1015 1020 Pro Pro Pro Lys Ala His Pro Arg Pro Pro Leu Pro Pro Gly Pro Ser 1025 1030 1035 1040 Pro Ala Ser Thr Phe Leu Gly Glu Val Ala Ser Gly Asp Asp Arg Ser 1045 1050 1055 Cys Ser Val Leu Gln Met Ala Lys Thr Leu Ser Glu Val Asp Tyr Ala 1060 1065 1070 Pro Ala Gly Pro Ala Ala Ser Ala Leu Leu Pro Gly Pro Leu Glu Leu 1075 1080 1085 Gln Pro Pro Pro Gly Thr Ala Leu Gly Leu Trp Pro Ala Pro Gln Leu 1090 1095 1100 Pro Ser Thr Pro His Pro Gly Glu His Pro Gly Arg Pro Gly Arg Gly 1105 1110 1115 1120 Gly Ser Val Pro Ala Gly Arg Ala Gly Gln Arg Ala Gly Arg Gly Arg 1125 1130 1135 His Glu Cys Leu Ala Ala Gly His Arg Leu Gly Ala Leu 1140 1145 942 amino acids amino acid linear protein Region 1..942 /note= “majptase” 6 Val Thr Val Pro Glu Pro Gly Ala Ala Glu Ser Arg Ala Pro Cys Gly 1 5 10 15 Asp Ser Ser Gly Gly Cys Val Arg Ser Ala Gly Ala Ser Met Asp Gln 20 25 30 Ser Val Ala Ile Gln Glu Thr Leu Ala Glu Gly Glu Tyr Cys Val Ile 35 40 45 Ala Val Gln Gly Val Leu Cys Glu Gly Asp Ser Arg Gln Ser Arg Leu 50 55 60 Leu Gly Leu Val Arg Tyr Arg Leu Glu His Gly Gly Gln Glu His Ala 65 70 75 80 Leu Phe Leu Tyr Thr His Arg Arg Met Ala Ile Thr Gly Asp Asp Val 85 90 95 Ser Leu Asp Gln Ile Val Pro Val Ser Arg Asp Phe Thr Leu Glu Glu 100 105 110 Val Ser Pro Asp Gly Glu Leu Tyr Ile Leu Gly Ser Asp Val Thr Val 115 120 125 Gln Leu Asp Thr Ala Glu Leu Ser Leu Val Phe Gln Leu Pro Phe Gly 130 135 140 Ser Gln Thr Arg Met Phe Leu His Glu Val Ala Arg Ala Cys Pro Gly 145 150 155 160 Phe Asp Ser Ala Thr Arg Asp Pro Glu Phe Leu Trp Leu Ser Arg Tyr 165 170 175 Arg Cys Ala Glu Leu Glu Leu Glu Met Pro Thr Pro Arg Gly Cys Asn 180 185 190 Ser Ala Trp Val Thr Trp Pro Gly Tyr Ala Thr Ile Gly Gly Gly Gly 195 200 205 Ser Asn Phe Asp Gly Leu Arg Pro Asn Gly Lys Gly Val Pro Met Asp 210 215 220 Gln Ser Ser Arg Gly Gln Asp Lys Pro Glu Ser Leu Gln Pro Arg Gln 225 230 235 240 Asn Lys Ser Lys Ser Glu Ile Thr Asp Met Val Arg Ser Ser Thr Ile 245 250 255 Thr Val Ser Asp Lys Ala His Ile Leu Ser Met Gln Lys Phe Gly Leu 260 265 270 Arg Asp Thr Ile Val Lys Ser His Leu Leu Gln Lys Glu Glu Asp Tyr 275 280 285 Thr Tyr Ile Gln Asn Phe Arg Phe Phe Ala Gly Thr Tyr Asn Val Asn 290 295 300 Gly Gln Ser Pro Lys Glu Cys Leu Arg Leu Trp Leu Ser Asn Gly Ile 305 310 315 320 Gln Ala Pro Asp Val Tyr Cys Val Gly Phe Gln Glu Leu Leu Leu Ser 325 330 335 Lys Glu Ala Phe Phe Phe His Asp Thr Pro Lys Glu Glu Glu Trp Phe 340 345 350 Lys Ala Val Ser Glu Gly Leu His Pro Asp Ala Lys Tyr Ala Lys Val 355 360 365 Lys Leu Ile Arg Leu Val Gly Ile Met Leu Leu Leu Tyr Val Lys Gln 370 375 380 Glu His Ala Ala Tyr Ile Ser Glu Val Glu Ala Glu Thr Val Gly Thr 385 390 395 400 Gly Ile Met Gly Arg Met Gly Asn Lys Gly Gly Val Ala Ile Arg Phe 405 410 415 Gln Phe His Asn Thr Ser Ile Cys Val Val Asn Ser His Leu Ala Ala 420 425 430 His Ile Glu Glu Tyr Glu Arg Arg Asn Gln Asp Tyr Lys Asp Ile Cys 435 440 445 Ser Arg Met Gln Phe Cys Gln Pro Asp Pro Ser Leu Pro Pro Leu Thr 450 455 460 Ile Ser Asn His Asp Val Ile Leu Trp Met Gly Asp Leu Asn Tyr Arg 465 470 475 480 Ile Glu Glu Leu Asp Val Glu Lys Val Lys Lys Leu Ile Glu Glu Lys 485 490 495 Asp Phe Gln Met Leu Tyr Ala Tyr Asp Gln Leu Lys Ile Gln Val Ala 500 505 510 Ala Lys Thr Val Phe Glu Gly Phe Thr Glu Gly Glu Leu Thr Phe Gln 515 520 525 Pro Thr Tyr Lys Tyr Asp Thr Gly Ser Asp Asp Trp Asp Thr Ser Glu 530 535 540 Lys Cys Arg Ala Pro Ala Trp Cys Asp Arg Ile Leu Trp Lys Gly Lys 545 550 555 560 Asn Ile Thr Gln Leu Ser Tyr Gln Ser His Met Ala Leu Lys Thr Ser 565 570 575 Asp His Lys Pro Val Ser Ser Val Phe Asp Ile Gly Val Arg Val Val 580 585 590 Asn Asp Glu Leu Tyr Arg Lys Thr Leu Glu Glu Ile Val Arg Ser Leu 595 600 605 Asp Lys Met Glu Asn Ala Asn Ile Pro Ser Val Ser Leu Ser Lys Arg 610 615 620 Glu Phe Cys Phe Gln Asn Val Lys Tyr Met Gln Leu Lys Val Glu Ser 625 630 635 640 Phe Thr Ile His Asn Gly Gln Val Pro Cys His Phe Glu Phe Ile Asn 645 650 655 Lys Pro Asp Glu Glu Ser Tyr Cys Lys Gln Trp Leu Asn Ala Asn Pro 660 665 670 Ser Arg Gly Phe Leu Leu Pro Asp Ser Asp Val Glu Ile Asp Leu Glu 675 680 685 Leu Glu Val Asn Lys Thr Thr Ala Thr Lys Leu Asn Ser Gly Glu Asp 690 695 700 Lys Ile Glu Asp Ile Leu Val Leu His Leu Asp Arg Gly Lys Asp Tyr 705 710 715 720 Phe Leu Ser Val Ser Gly Asn Tyr Leu Pro Ser Cys Phe Gly Ser Pro 725 730 735 Ile His Thr Leu Cys Tyr Met Arg Glu Pro Ile Leu Asp Leu Pro Leu 740 745 750 Glu Thr Ile Ser Glu Leu Thr Leu Met Pro Val Trp Thr Gly Asp Asp 755 760 765 Gly Ser Gln Leu Asp Ser Pro Met Glu Ile Pro Lys Glu Leu Trp Met 770 775 780 Met Val Asp Tyr Leu Tyr Arg Asn Ala Val Gln Gln Glu Asp Leu Phe 785 790 795 800 Gln Cys Pro Gly Leu Arg Ser Glu Phe Glu His Ile Arg Asp Cys Leu 805 810 815 Asp Thr Gly Met Ile Asp Asn Leu Ser Ala Ser Asn His Ser Val Ala 820 825 830 Glu Ala Leu Leu Ile Phe Leu Glu Ser Leu Pro Glu Pro Val Ile Cys 835 840 845 Tyr Ser Thr Tyr His Asn Cys Leu Glu Cys Ser Gly Asn Tyr Thr Ala 850 855 860 Ser Lys Gln Val Ile Ser Thr Leu Pro Ile Phe His Lys Asn Val Phe 865 870 875 880 His Tyr Leu Met Ala Phe Leu Arg Glu Leu Leu Lys Asn Ser Ala Lys 885 890 895 Asn His Leu Asp Glu Asn Ile Leu Ala Ser Ile Phe Gly Ser Leu Leu 900 905 910 Leu Arg Asn Pro Ala Gly His Gln Lys Leu Asp Met Thr Glu Lys Lys 915 920 925 Lys Ala Gln Glu Phe Ile His Gln Phe Leu Cys Asn Pro Leu 930 935 940 968 amino acids amino acid linear protein Region 1..968 /note= “ocr1” 7 Met Lys Phe Phe Val Phe Lys Ser Phe Leu ser Asp Cys Tyr Arg Ser 1 5 10 15 Leu Leu Asp Lys Ser Gln Leu Pro Ala Pro Arg Ser Arg Leu Pro Ala 20 25 30 Pro Gly Ala Arg Arg Gly Ala Val Pro Gln Thr Thr Arg Ser Arg Gly 35 40 45 Gly Trp Val Trp Gly Arg Gly Ser Gln Cys Arg Arg Ile Gly Pro Gln 50 55 60 Ser Ala Val Leu Leu Ser Pro Glu Ala Ala Trp Met Glu Pro Pro Leu 65 70 75 80 Pro Val Gly Ala Gln Pro Leu Ala Thr Val Glu Gly Met Glu Met Lys 85 90 95 Gly pro Leu Arg Glu Pro Cys Ala Leu Thr Leu Ala Gln Arg Asn Gly 100 105 110 Gln Tyr Glu Leu Ile Ile Gln Leu His Glu Lys Glu Gln His Val Gln 115 120 125 Asp Ile Ile Pro Ile Asn Ser His Phe Arg Cys Val Gln Glu Ala Glu 130 135 140 Glu Thr Leu Leu Ile Asp Ile Ala Ser Asn Ser Gly Cys Lys Ile Arg 145 150 155 160 Val Gln Gly Asp Trp Ile Arg Glu Arg Arg Phe Glu Ile Pro Asp Glu 165 170 175 Glu His Cys Leu Lys Glu Leu Ser Ala Val Leu Ala Ala Gln Lys Ala 180 185 190 Gln Ser Gln Leu Leu Val Pro Glu Gln Lys Asp Ser Ser Ser Trp Tyr 195 200 205 Gln Lys Leu Asp Thr Lys Asp Lys Pro Ser Val Phe Ser Gly Leu Leu 210 215 220 Gly Phe Glu Asp Asn Phe Ser Ser Met Asn Leu Asp Lys Lys Ile Asn 225 230 235 240 Ser Gln Asn Gln Pro Thr Gly Thr His Arg Glu Pro Pro Pro Pro Pro 245 250 255 Phe Ser Val Asn Lys Met Leu Pro Arg Glu Lys Glu Ala Ser Asn Lys 260 265 270 Glu Gln Pro Lys Val Thr Asn Thr Met Arg Lys Phe Phe Val Pro Asn 275 280 285 Thr Gln Ser Gly Gln Arg Glu Gly Leu Ile Lys His Ile Leu Ala Lys 290 295 300 Arg Glu Lys Glu Tyr Val Asn Ile Gln Thr Phe Arg Phe Phe Val Gly 305 310 315 320 Thr Trp Asn Val Asn Gly Gln Ser Pro Asp Ser Gly Leu Glu Pro Trp 325 330 335 Leu Asn Cys Asp Pro Asn Pro Pro Asp Ile Tyr Cys Ile Gly Phe Gln 340 345 350 Glu Leu Leu Leu Ser Thr Glu Ala Phe Phe Tyr Phe Glu Ser Val Lys 355 360 365 Glu Gln Glu Trp Ser Met Ala Val Glu Arg Gly Leu His Ser Lys Ala 370 375 380 Lys Tyr Lys Lys Val Gln Leu Val Arg Leu Val Gly Met Met Leu Leu 385 390 395 400 Ile Phe Ala Arg Lys Asp Gln Cys Arg Tyr Ile Arg Asp Ile Ala Thr 405 410 415 Glu Thr Val Gly Thr Gly Ile Met Gly Lys Met Gly Asn Lys Gly Gly 420 425 430 Val Ala Val Arg Phe Val Phe His Asn Thr Thr Phe Cys Ile Val Asn 435 440 445 Ser His Leu Ala Ala His Val Glu Asp Leu Glu Arg Arg Asn Gln Asp 450 455 460 Tyr Lys Asp Ile Cys Ala Arg Met Ser Phe Val Val Pro Asn Gln Thr 465 470 475 480 Leu Pro Gln Leu Asn Ile Met Lys His Glu Val Val Ile Trp Met Gly 485 490 495 Asp Leu Asn Tyr Arg Leu Cys Met Pro Asp Ala Asn Glu Val Lys Ser 500 505 510 Leu Ile Asn Lys Lys Asp Leu Gln Arg Leu Leu Lys Phe Asp Gln Leu 515 520 525 Asn Ile Gln Arg Thr Gln Lys Lys Ala Phe Val Asp Phe Asn Glu Gly 530 535 540 Glu Ile Lys Phe Ile Pro Thr Tyr Lys Tyr Asp Ser Lys Thr Asp Arg 545 550 555 560 Trp Asp Ser Ser Gly Lys Cys Arg Val Pro Ala Trp Cys Asp Arg Ile 565 570 575 Leu Trp Arg Gly Thr Asn Val Asn Gln Leu Asn Tyr Arg Ser His Met 580 585 590 Leu Leu Lys Thr Ser Asp His Lys Pro Val Ser Ala Leu Phe His Ile 595 600 605 Gly Val Lys Val Val Asp Glu Arg Arg Tyr Arg Lys Val Phe Glu Asp 610 615 620 Ser Val Arg Ile Met Asp Arg Met Glu Asn Asp Phe Leu Pro Ser Leu 625 630 635 640 Glu Leu Ser Arg Arg Glu Phe Val Phe Glu Asn Val Lys Phe Arg Gln 645 650 655 Leu Gln Lys Gly Lys Phe Gln Ile Ser Asn Asn Gly Gln Val Pro Cys 660 665 670 His Phe Ser Phe Ile Pro Lys Leu Asn Asp Ser Gln Tyr Cys Lys Pro 675 680 685 Trp Leu Arg Ala Glu Pro Phe Glu Gly Tyr Leu Glu Pro Asn Glu Thr 690 695 700 Val Asp Ile Ser Leu Asp Val Tyr Val Ser Lys Asp Ser Val Thr Ile 705 710 715 720 Leu Asn Ser Gly Glu Asp Lys Ile Glu Asp Ile Leu Val Leu His Leu 725 730 735 Asp Arg Gly Lys Asp Tyr Phe Leu Thr Ile Ser Gly Asn Tyr Leu Pro 740 745 750 Ser Cys Phe Gly Thr Ser Leu Glu Ala Leu Cys Arg Met Lys Arg Pro 755 760 765 Ile Arg Glu Val Pro Val Thr Lys Leu Ile Asp Leu Glu Lys Ser Leu 770 775 780 Leu Gln Met Val Pro Leu Asp Glu Gly Ala Ser Glu Arg Pro Leu Gln 785 790 795 800 Val Pro Lys Glu Ile Trp Leu Leu Val Asp His Leu Phe Lys Tyr Ala 805 810 815 Cys His Gln Glu Asp Leu Phe Gln Thr Pro Gly Met Gln Glu Glu Leu 820 825 830 Gln Gln Ile Ile Asp Cys Leu Asp Thr Ser Ile Pro Glu Thr Ile Pro 835 840 845 Gly Ser Asn His Ser Val Ala Glu Ala Leu Leu Ile Phe Leu Glu Ala 850 855 860 Leu Pro Glu Pro Val Ile Cys Tyr Glu Leu Tyr Gln Arg Cys Leu Asp 865 870 875 880 Ser Ala Tyr Asp Pro Arg Ile Cys Arg Gln Val Ile Ser Gln Leu Pro 885 890 895 Arg Cys His Arg Asn Val Phe Arg Tyr Leu Met Ala Phe Leu Arg Glu 900 905 910 Leu Leu Lys Phe Ser Glu Tyr Asn Ser Val Asn Ala Asn Met Ile Ala 915 920 925 Thr Leu Phe Thr Ser Leu Leu Leu Arg Pro Pro Pro Asn Leu Met Ala 930 935 940 Arg Gln Thr Pro Ser Asp Arg Gln Arg Ala Ile Gln Phe Leu Leu Gly 945 950 955 960 Phe Leu Leu Gly Ser Glu Glu Asp 965 121 amino acids amino acid linear protein Region 1..121 /note= “arab5ptase” 8 Ser Gly Glu Lys Asp Thr Asp Gln Glu Lys Arg Asn Asp Asp Val Arg 1 5 10 15 Glu Ile His Arg Arg Thr Gln Phe Leu Pro His Ser Leu Asn Ala Asn 20 25 30 Glu Leu Pro Arg Ser Ile Cys Asn His Glu Arg Ile Ile Asn Met Gly 35 40 45 Asp Leu Asn Tyr Arg Ile Asn Leu Ser Tyr Glu Lys Thr His Glu Leu 50 55 60 Ile Ala Arg Lys Ser Trp Gln Arg Leu Val Glu Tyr Asp Gln Leu Ser 65 70 75 80 Arg Glu Met Thr Lys Gly Asn Leu Phe Glu Gly Trp Ser Glu Gly Thr 85 90 95 Leu Asp Phe Ala Pro Thr Tyr Lys Tyr Glu Ser Ile Gln Lys Ile Thr 100 105 110 Ser Glu Met Thr Arg Asn Pro Gly Thr 115 120 412 amino acids amino acid linear protein Region 1..412 /note= “c5ptase43” 9 Met Ala Gly Lys Ala Ala Ala Pro Gly Thr Ala Val Leu Leu Val Thr 1 5 10 15 Ala Asn Val Gly Ser Leu Phe Asp Asp Pro Glu Asn Leu Gln Lys Asn 20 25 30 Trp Leu Arg Glu Phe Tyr Gln Val Val His Thr His Lys Pro His Phe 35 40 45 Met Ala Leu His Cys Gln Glu Phe Gly Gly Lys Asn Tyr Glu Ala Ser 50 55 60 Met Ser His Val Asp Lys Phe Val Lys Glu Leu Leu Ser Ser Asp Ala 65 70 75 80 Met Lys Glu Tyr Asn Arg Ala Arg Val Tyr Leu Asp Glu Asn Phe Lys 85 90 95 Ser Gln Glu His Phe Thr Ala Leu Gly Ser Phe Tyr Phe Leu His Glu 100 105 110 Ser Leu Lys Asn Ile Tyr Gln Phe Asp Phe Lys Ala Lys Lys Tyr Lys 115 120 125 Lys Val Thr Gly Lys Glu Ile Tyr Ser Asp Thr Leu Glu Ser Thr Pro 130 135 140 Met Leu Glu Lys Glu Lys Phe Pro Gln Asp Tyr Phe Pro Glu Cys Lys 145 150 155 160 Trp Ser Arg Lys Gly Phe Val Arg Thr Arg Trp Cys Val Ala Asp Cys 165 170 175 Ala Phe Asp Leu Val Asn Ile His Leu Phe His Asp Ala Ser Asn Leu 180 185 190 Val Ala Trp Glu Thr Ser Pro Ser Leu Tyr Ser Gly Ile Arg His Lys 195 200 205 Ala Leu Gly Tyr Val Leu Asp Arg Ile Ile Asp Gln Arg Phe Glu Lys 210 215 220 Val Ser Tyr Phe Val Phe Gly Asp Glu Asn Phe Arg Leu Asp Ser Lys 225 230 235 240 Ser Val Val Glu Thr Leu Cys Thr Lys Ala Thr Met Gln Thr Val Arg 245 250 255 Ala Ala Asp Thr Asn Glu Val Val Lys Leu Ile Phe Arg Glu Ser Asp 260 265 270 Asn Asp Arg Lys Val Met Leu Gln Leu Glu Lys Lys Leu Phe His Tyr 275 280 285 Phe Asn Gln Glu Val Phe Arg Asp Asn Asn Gly Thr Ala Asp Leu Glu 290 295 300 Phe Asp Lys Glu Leu Ser Val Phe Lys Asp Arg Leu Tyr Glu Leu Asp 305 310 315 320 Ile Ser Phe Pro Pro Ser Tyr Pro Tyr Ser Glu Asp Ser Gly Gln Gly 325 330 335 Arg Gln Tyr Met Asn Thr Arg Cys Pro Ala Trp Cys Asp Arg Val Leu 340 345 350 Met Ser Pro Ser Ala Arg Glu Leu Ile Leu Lys Ser Glu Ser Glu Glu 355 360 365 Lys Val Val Thr Tyr Asp His Ile Gly Pro Asn Val Cys Met Gly Asp 370 375 380 His Lys Pro Val Phe Leu Ala Phe Arg Ile Ala Pro Gly Ala Gly Lys 385 390 395 400 Pro His Ala His Val His Lys Cys Cys Val Val Gln 405 410 654 amino acids amino acid linear protein Region 1..654 /note= “consensus” 10 Glu Leu Arg Val Ser Ala Glu Ser Arg Ala Cys Ala Ala Phe Val Val 1 5 10 15 Ser Gly Arg Ser Val Cys Ala Ser Cys Ser Gln Leu Pro Glu Ser Pro 20 25 30 Leu Pro Val Gly Gln Pro Ala Leu Phe Ser His Gly Ser Leu Thr Glu 35 40 45 Val Glu Phe Thr Leu Ala Arg Gln Gly Glu Leu Glu Leu Ser Leu Glu 50 55 60 Val Phe Asp Gln Ser Pro Ala Glu Gln Leu Leu Pro Gly Glu Ser Ile 65 70 75 80 Val Lys Leu Ser Leu Ser Leu Ser Ser Ile Lys Leu Leu Leu Leu Ser 85 90 95 Ala Ala Glu Arg Pro Pro Ser Ala Phe Glu Val Lys Leu Asp Ile Ser 100 105 110 Gly Lys Val Asp Val Glu Lys Leu Ile Gln Pro Ser Leu Asp Ser His 115 120 125 Ile Gln Leu Ile Ser Gln Lys Asn Lys Leu Glu Glu Lys Val Arg Lys 130 135 140 Phe Ile Phe Lys Lys Glu Arg Phe Gln Leu Gln Leu Lys Asn Lys Ser 145 150 155 160 Tyr Glu Pro Ile Ile Phe Gly Thr Trp Asn Gly Pro Lys Thr Ser Trp 165 170 175 Leu Ile Lys Gly Gln Gly Lys Thr Asp Asp Glu Ile Pro Asp Ile Tyr 180 185 190 Val Ile Gly Leu Gln Phe Ala Glu Leu Ser Ala Leu Lys Gln Glu Trp 195 200 205 Phe Ala Ser Gly Leu Thr Asp Tyr Lys Lys Val Ala Leu Leu Lys Thr 210 215 220 Leu Gly Ile Met Leu Leu Ile Phe Lys Glu His Glu Asn Ile Ser His 225 230 235 240 Ile Glu Thr Thr Val Lys Thr Gly Ile Gly Gly Asn Lys Gly Ala Val 245 250 255 Val Arg Phe Phe Thr Ser Phe Phe Val Asn Ser His Leu Ala Ala Gly 260 265 270 Glu Asn Tyr Glu Arg Arg Asn Cys Asp Tyr Lys Asp Ile Arg Arg Ser 275 280 285 Phe Gly Asp Pro Leu Leu Leu Arg Ile Thr His Ile Phe Trp Phe Gly 290 295 300 Asp Leu Asn Tyr Arg Asp Met Asp Glu Glu Val Leu Ile Lys Arg Lys 305 310 315 320 Glu Gln Arg Leu Leu Glu Tyr Asp Gln Leu Asn Arg Thr Gly Lys Phe 325 330 335 Leu Gly Phe Glu Gly Glu Ile Thr Phe Pro Pro Thr Tyr Lys Tyr Arg 340 345 350 Gly Arg Asp Tyr Ala Tyr Lys Gln Lys Asp Thr Ser Glu Lys Thr Arg 355 360 365 Val Pro Ala Trp Cys Asp Arg Ile Leu Trp Lys Gly Thr Gln Leu Val 370 375 380 Cys Ser Tyr Gly Ser Met Asp Ile Thr Ser Asp His Lys Pro Val Phe 385 390 395 400 Ala Thr Phe Arg Ile Gly Val Thr Gln Phe Val Ser Lys Val Val Glu 405 410 415 Thr Leu Tyr Arg Gln Ile Glu Glu Val Arg Ile Ser Arg Val Leu Phe 420 425 430 Arg Phe Cys Glu Lys Glu Glu Ser Asn Val Lys Phe Val Phe Ser Glu 435 440 445 Pro Lys Gln Leu Leu Tyr Cys Lys Ser Asp Ala Glu Tyr Gly Lys Ala 450 455 460 Leu Lys Leu Glu Pro Thr Ala Ile Leu Thr Leu Leu Val His Lys Gly 465 470 475 480 Glu Leu Thr Gly Leu Ser Gly Glu Asp Lys Ile Asp Ile Val Leu His 485 490 495 Leu Arg Lys Tyr Phe Leu Ser Gly Asn Pro Ser Cys Phe Gly Thr Ser 500 505 510 Leu Cys Glu Pro Ile Pro Thr Glu Leu Cys Ser Leu Ser Glu Asp Glu 515 520 525 Gly Pro Pro Pro Glu Trp Val Asp Leu Pro Ala Pro Gln Glu Asp Leu 530 535 540 Phe Gln Gln Pro Glu Leu Ile Asp Cys Leu Asp Thr Ser Pro Ala Ser 545 550 555 560 Asn His Ser Val Ala Ala Leu Leu Leu Pro Leu Leu Pro Pro Val Ile 565 570 575 Cys Tyr Cys Leu Ala Thr Pro Ala Val Ile Ser Leu Pro Arg Phe His 580 585 590 Asn Val Phe Tyr Leu Met Phe Leu Arg Glu Leu Lys Pro Pro Asn Asn 595 600 605 Pro Ala Ile Ser Leu Leu Arg Pro Ala Gly Ala Arg Gly Pro Pro Lys 610 615 620 Gln Pro Phe Leu Phe Leu Cys Ser Ser Ala Gly Asp Ser Lys Thr Ser 625 630 635 640 Leu Pro Pro Gly Ser Thr Pro Pro Gly Arg Gly Arg Cys Ala 645 650 

What is claimed is:
 1. A substantially pure polypeptide, comprising an amino acid sequence that is substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2), or biologically active fragments thereof.
 2. The substantially pure polypeptide of claim 1, wherein said polypeptide comprises the amino acid sequence shown in FIG. 10 (SEQ ID NO:2) or biologically active fragments thereof.
 3. The substantially pure polypeptide of claim 1, wherein said polypeptide further comprises a heterologous protein fused to said amino acid sequence that is substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2), or biologically active fragments thereof.
 4. A pharmaceutical composition, comprising an effective amount of the polypeptide of claim 1 in combination with a pharmaceutically acceptable carrier.
 5. The substantially pure polypeptide of claim 1, wherein said polypeptide comprises an inositol polyphosphate 5-phosphatase activity, whereby said polypeptide is capable of hydrolyzing a 5-phosphate from Ins(1,3,4,5)P₄ and PtdIns(3,4,5)P₃, but not Ins(1,4,5)P₃ or PtdIns(4,5)P₂.
 6. The substantially pure polypeptide of claim 1, wherein said polypeptide is capable of associating with GRB2.
 7. The substantially pure polypeptide of claim 1, wherein said polypeptide is capable of binding a GRB2—SH3 domain.
 8. An isolated nucleic acid segment, said nucleic acid segment encoding a polypeptide having an amino acid sequence substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2), or biologically active fragments thereof.
 9. The isolated nucleic acid segment of claim 8, wherein said nucleic acid segment comprises at least about 15 contiguous nucleotides from a nucleotide sequence that is substantially homologous to the nucleotide sequence shown in FIG. 10 (SEQ ID NO:1).
 10. The isolated nucleic acid segment of claim 9, wherein said nucleic acid segment comprises at least about 15 contiguous nucleotides from the nucleic acid segment as shown in FIG. 10 (SEQ ID NO:1).
 11. The isolated nucleic acid segment of claim 8, wherein said nucleic acid segment encodes a polypeptide having an inositol polyphosphate 5-phosphatase activity, whereby said polypeptide is capable of hydrolyzing a 5-phosphate from Ins(1,3,4,5)P₄ and PtdIns(3,4,5)P₃, but not Ins(1,4,5)P₃ or PtdIns(4,5)P₂.
 12. The isolated nucleic acid segment of claim 8, wherein said nucleic acid further comprises a segment which encodes a heterologous protein, whereby said nucleic acid is expressed as a fusion protein.
 13. An expression vector, said expression vector comprising a nucleic acid segment operably linked to a promoter sequence, wherein said nucleic acid segment is the nucleic acid of claim
 8. 14. A recombinant host cell, wherein said host cell has been transfected with the expression vector of claim 13, whereby said host cell is capable of expressing said nucleic acid segment.
 15. The recombinant host cell of claim 14, wherein said host cell is selected from the group consisting of bacterial, mammalian, plant, fungal and insect cells.
 16. The recombinant host cell of claim 15, wherein said host cell is an Sf9 insect cell.
 17. An isolated antibody, said antibody being specifically immunoreactive with a polypeptide having an amino acid sequence substantially homologous to the amino acid sequence shown in FIG. 10 (SEQ ID NO:2) or its biologically active fragments.
 18. The isolated antibody of claim 17, wherein said antibody is capable of blocking or inhibiting one or more biological activities of the polypeptide having the amino acid sequence shown in FIG. 10 (SEQ ID NO:2).
 19. The isolated antibody of claim 17, wherein said antibody is specifically immunoreactive with a polypeptide having the amino acid sequence shown in FIG. 10 (SEQ ID NO:2).
 20. The isolated antibody of claim 17, wherein said antibody is a monoclonal antibody.
 21. A pharmaceutical composition, comprising an effective amount of the isolated antibody of claim 17 in combination with a pharmaceutically acceptable carrier.
 22. A method of preparing a substantially pure polypeptide having inositol polyphosphate 5-phosphatase activity, comprising: inserting the nucleic acid segment of claim 8, into an expression vector; transfecting a host cell capable of expressing said nucleic acid segment with said expression vector; culturing said host cell under conditions which result in expression of said nucleic acid segment; and recovering said protein having inositol polyphosphate 5-phosphatase activity.
 23. A method of determining whether a test compound is an agonist or antagonist of a GRB2/GA5Ptase interaction, the method comprising: contacting GRB2 with GA5Ptase or a biologically active fragment thereof, under conditions conducive to forming a GRB2/GA5Ptase complex, in the presence and absence of the test compound; and determining the amount of GRB2/GA5Ptase complex formed in the presence and absence of said test compound, an increase or decrease in the amount of GRB2/GA5Ptase complex formed in the presence of said test compound being indicative that the test compound is an agonist or antagonist of GRB2/GA5Ptase interaction, respectively.
 24. A method for determining whether a test compound is an agonist or antagonist of an inositol polyphosphate 5-phosphatase activity, comprising: incubating a mixture of inositol polyphosphate substrate and GA5Ptase, in the presence and absence of the test compound; assaying the mixture to determine an amount of a product of GA5Ptase activity on said inositol polyphosphate substrate in the presence and absence of the test compound; and comparing the amount of product of GA5Ptase activity in the presence of the test compound to the amount of product of GA5Ptase activity in the absence of the test compound, an increase or decrease in the amount of product of GA5Ptase activity in the presence of the test compound being indicative that the test compound is an agonist or antagonist of an inositol polyphosphate 5-phosphatase activity, respectively.
 25. The method of claim 24, wherein said inositol polyphosphate substrate is selected from the group consisting of Ins(1,3,4,5)P₄ and PtdIns(3,4,5)P₃.
 26. A method of identifying the presence of GRB2 in a sample, comprising incubating said sample with the polypeptide of claim 6, and detecting binding between said polypeptide and a portion of said sample, said binding being indicative of the presence of GRB2 in said sample.
 27. A method of purifying GRB2 from a mixture of different proteins containing GRB2, comprising: immobilizing the polypeptide of claim 6, on a solid support; contacting said mixture of proteins with said solid support under conditions in which said polypeptide binds GRB2; washing said solid support to remove unbound proteins; and eluting GRB2 from said solid support in substantially pure form.
 28. A kit for determining whether a test compound is an agonist or antagonist of GA5Ptase activity, comprising: a GA5Ptase polypeptide, or catalytically active fragment thereof; a GA5Ptase substrate; and instructions for assaying for the presence of said substrate and a product of GA5Ptase.
 29. The kit of claim 26, wherein said GA5Ptase substrate is selected from the group consisting of Ins(1,3,4,5)P₄ and PtdIns(3,4,5)P₃.
 30. The kit of claim 26, wherein said GA5Ptase and said substrate are lyophilized, and further comprising a buffer solution for reconstituting said GA5Ptase and said substrate.
 31. A method of treating a patient suffering from a proliferative disorder, the method comprising administering to said patient a therapeutically effective amount of the polypeptide of claim
 6. 32. A substantially pure polypeptide, said polypeptide being immunologically cross-reactive with an antibody to a GA5ptase protein, or biologically active fragment thereof. 